[mjuhl24]

It really depends on the instrument. While there are many instruments that are fairly easy to "teach" yourself, in almost all cases it is good to have someone guide you in the learning process. There is so much information available on the internet for free, and with instruments like guitar it is easy to get started on your own - but even then you should seek advice from someone who plays. Most professional or even intermediate musicians will be able to give you some good tips just by watching and listening to you for a few minutes.

If you're looking to learn something like viola or trombone, you will almost definitely want to take lessons.

One great resource is undergraduate music students. They are generally desperate for income (I know from experience) and would probably be willing to take a few minutes to help you out.

[mhidalgo]

I would say Guitar and Piano are the instruments I would like to pick up

[mjuhl24]

These are two instruments that you can do a lot with on your own.

I learned to play guitar [mostly] on my own, with information I found on the internet. I would recommend that you pick up a decent acoustic guitar and google 'beginning guitar' and start from there. It's really helpful once you've piddled with it some to have someone else who plays decently listen to you. Guitar lessons are usually rather cheap, too, if you want to go that route. Even just a few lessons could really get you started.

Piano is a little more complicated. You can do a lot with a piano if you have a good ear and good coordination. For me, personally, piano is a struggle and has taken a lot more work/patience/practice. Most likely, if you want to play piano you'll definitely need lessons.

The good thing is that there are always a lot of people who play these two instruments, and a lot of them give lessons for reasonable prices.