I would like to be able to record my music and put it online, or on my ipod. While i know how to do that part, how do i capture the sound?? I have a Raven amp- one with a line in output. How do i get my music to the computer? Can i buy a mic, can i connect it to the hard drive on my computer?
Any help would be appreciated.
There is a device that will allow you to directly connect your instrument to the computer.
I'm not sure what it's called.
Check your local music store.
Firstly if you're planning on Mic'ing up the amp i'd get a mic first, there are plenty of good ones out there for guitar amp recording, my personal preference is the Shure SM57.

Next you'll need an interface so you can plug the mic via XLR cable into the computer. Again there are plenty of good interfaces out there, my personal prefernce is the MOTU Ultralite, but it might be a bit expensive.

Next you'll need a program to capture the sounds from the amp, through the microphone, through the interface into the computer with. Again there is lots of good software, Audacity is good for beginners and i hear Reaper's pretty decent too.

Lastly practise with setups and getting to know the different sounds acheiveable by different mic placements and types.

Hope this helps.
All those suggestions are great and will work well (lots more to those music production programs though, but just takes time getting to know one)

Anyway, there's another way to do it as simple as: play guitar, transfer file to ipod or CD, done:

Use a portable digital recorder like this:

you will have to test it in different locations/distances from your amp to get what you want. It won't be nearly as good quality as mic'ing to a sequencer and it's just you playing guitar so no drum options but it will definitely get your sound on your ipod or CD real quick and easy.

BTW, lots of pros use these during jam sessions in the creation phase of their songs to remember riffs for later.