Provide some tips for those who would like to learn how to play an instrument.

Well, first, there has to be interest. There also has to be some aptitude for the instrument/instruments of choice as some are extremely difficult to learn much less play. Once an instrument has been chosen, play around with the instrument for a while (before taking lessons) to see if you can get the thing sounding somewhat musical. Once that is shown, then start taking lessons to learn the basics of the instrument and to learn to read music. Practice on your own as much as is humanly possible in between lessons. Give yourself goals as to learning pieces, riffs, scales, modes or plain ole' listening to records and learning by ear lead lines, melodies, chords, etc. note for note. Developing a good ear and feel are the most important attributes to playing well. Anyone can learn to read music but if you can't convey a 'feel' of a musical piece, you'll never get work. This is just my experience and opinions.

Right on DW-
not much to add, except to say go be like one of those higly irritating teenage rock stars that hang out at the mega-music store, and just spend a few hours playing different instruments. Go pound on the drums, see if you can keep a straight 1 2 3 4 on the bass drum while doing 2 4 on the hi-hat and 1 3 on the snare. If you can do it first try, you're a drummer, go for it...that's the biggest thing with drums, is being able to tell each arm and leg to do something different and have them respond properly. (You won't believe how many can't do it, so don't feel bad if you can't, just move on to something else...can you pat your stomach and rub your head at the same time? )
If your hands are large, electric guitar may be more difficult; try a bass. It requires a different strength level, though, due to heavier string tensions to overcome when pushing down to play a note. If you can fly on a computer keyboard, consider a piano....ten fingers working in unison sounds awesome. Again, though, there will be requirements of co-ordination and lots of work.
Everybody wants to be a lead guitarist apparently at some point, so feel free to try one out- stay away from cheap instruments though, or you'll get discouraged....the more expensive ones are easier to play in general.
I guess that hold true for all instruments; buy used when you can ( these things de-value more than cars....) and that way you aren't out rent money too.
Lots of aids available to learn guitar these days too, programs that walk you through step by step. Check out Guitar Center's teaching website- they have some great resources, and a lot of it is free. (They like to sell guitars, so they will be helpful.)
Last thing- don't give up practicing when your fingers are sore- just give them a break for a day. You have to develop callouses or "hide" to play for longer periods of time....but please stop if you're bleeding- it's gonna take longer to heal, and you'll play less.
Like Dave said, desire is first, and feel....if you have those, you're on your way.

As one who's given up two instruments for lack of time and privacy, I'd like to add:
A place to practice without interference from neighbors, family members, etc.
Some would-be musicians don't care about disturbing other people (or fear the inevitable "cut out that racket!" for the equally inevitable miscues), but if you're like me, you want to respect others' desire for quietude and, at the same time, want to be free to experiment, make mistakes, play it loud or soft. So do take these things into consideration before taking the plunge.
By the way, I first tried the saxophone - so impressed I was with Marc Colby's solo on Maynard Ferguson's "Primal Scream." I was assigned to a Navy ship at the time, and had no place to practice and very little time. I think I would have been an okay saxman if I stuck with it. I did get into it enough to teach myself the main melodies of As Time Goes By and the aforementioned Primal Scream (although I hadn't graduated to trying the solo.)
At the time, I had remote aspirations to actually being able to join a nightclub band and play some of my favorite jazz pieces along with whatever pop or R&B tunes they required.
Several years later, on a whim, I bought a portable keyboard from Sears - althouth the sax is still my favorite instrument, I thought I could handle the keyboard more easily, I'd been impressed by the work of a guy named Schuu and I wouldn't have to worry about reeds.
Ultimately, I want to try that again - even if only for personal amusement. I passed my keyboard on because a musician at the church I attended at the time, he was the drummer, had expressed interest in learning the keyboard, so I gave it to him as a gift.
I plan to get back into it when I'm able to add a room to my house (or have a house built), a room where I can store the keyboard and all my "toys".

Ooh, I forgot a few of things.
First, when I was in high school, I took guitar lessons briefly.
That was a complete waste.
I saw an ad by Roy Clark on playing guitar made easy. I just haaaaaad to check it out. So my mother bought me a used acoustic guitar, and I took a few lessons and soon got bored with it.
Well, I suppose Clark's method was easy, but I never really cared for it. I might have liked the bass, but I just couldn't get into the guitar.
When I was 6, my older sister tried to enroll me in a piano class. Before I even touched a key, I looked at the sheet music - and ran like the Peruvian guide when he saw that idol in the jungle during Raiders of the Lost Ark.
Also, inspired by The Beatles' Saturday morning cartoon, I got my mom to buy me one of those cheapo drum sets. Well, I had no teacher and, apparently, no rhythm. (I'd completely forgotten about that until now.) What made me think of it was this:
Toward the end of my 6th grade year, the junior high band director invited those of us who wanted to play an instrument to sign up before the end of the school. I wanted to play drums. So did about 15 other boys. With that much competition, I didn't think I had a chance, so I passed.

Woody
about the practice thing.... that's what headphones are for- you used to be able to get this little effects box/headphone amp (that was made by a guy named Tom Sholz, of Boston fame)
rockman amp

A good friend loaned me his, while I was re-learning the bass after 15 years.....saved my marriage, I bet. Little box sounded great!
Once you feel you're good enough to play on a stage, try going in before or after a rehersal with the church band or a local club that you know the owner of, stuff like that.....a big enough place to hear how your amp/guitar (or whatever) combined sounds like, and away from the house and neighbors. Heck, I know of one local band that rented one of those storage building units, and would practice there in the evenings....actually became a problem, because they were good, and folks started coming to hear them, but since it had electric gates, nobody could get in, and cars parked all over the place became an issue.
Dream for a problem like that, OK? Go for it- I started on piano, then electric guitar, then bass....I can deal with one note at a time better than chords and inversions etc.
Sax, well, there's no way to play it soft, so you may have to rent one of those units just to save your family's ears. I say grab a bass, and join us low end-ers, kings of sub.
Later
TonyY

Tony, you nut. LOL
Yeah, I know the headset will be fine on a keyboard, but I can't see it being of much use with a sax.
Anyway, as I mentioned before, my interests have evolved to where I'd rather play the keys. Of course, I once had this fantasy of emulating McCartney on the left-handed, violin-shaped bass.
The real question is: Am I coordinated enough to be able to play - AND sing! hahahaha

I had a friend, Debbie, who lived somewhere in Louisiana - Baton Rouge, I think - who played guitar in a band. She was a big fan of Heart, and said that's the toughest thing to do: to play and sing at the same time ... especially on a song like Crazy on You.

Listen to music you want to play. When I first started on guitar, I listened to blues records and just emulated what I heard. Plus, it keeps you interested in the instrument

MikeI like your advice & i feel your soo right!
As Jay Beckenstein once told me "play what gives you goosebumps ".
Everytime i start finding myself getting to ; robot like, i think of that!
Mandi

Hey Woody-
That's true, singing and playing takes a lot of practice and not everybody can do it well, but it's actually a great way to develop your skills; if you can sing it, try to play it- it'll help you determine the key, the mode, the meter, etc......I don't sing, can't rub my head and pat my belly at the same time (but I can do the vulcan greeting, which I've noticed a lot of people can't get- too hard to get the fingers to operate seperately) but if I can hear it in my head, then I can usually pick it out as I go.
Mike is on target too, just have to be careful that you don't get stuck in a rut though, playing the same style all the time. We all need to listen to a wide variety of music, to help train our ears and broaden our range of styles.
I feel like a successful musician when the tune in my head gets connected to the fingers and it's almost automatic. Love that feeling.
TonyY