Hey guys, so when it comes to mis and recording i'm a total idiot, so I just purchased a sm57 shure microphone, and i connected through my guitar amp, now the only problem is that the volume input is too low... in order to be able to sing off of it, I need to put the volume really high, but it throws off my guitar volume, is there some sort of piece im missing to this? please help!! thanks
Putting both through your amp might not be such a good idea, especially for recording. You should get an interface for that. For practicing get a PA system. If you can't afford one you could borrow a friend's bass or keyboard amp. I found those work as well but the quality isn't as good as the PA's.
As stated before, you should buy an audio interface.
Adapting a cable to plug a mic into a guitar amp simply wont work as the resistance is different between instrument and mic level devices.

I suggest just buying an audio interface with one or two mic inputs on it....usually they are of the XLR type. You will be able to mic your guitar amp and record that, play it back, and track any vocals needed.

See my UG Recording Videos (linked in my sig) for help.
hmm ok thanks guys, appreciate all the help... also, can they be used to play live? If so, what can I do about the volume problem with that? will the audio interface help with that?
No. Interfaces are for recording. Essentially, they allow your microphones and line-input devices to connect with - or interface with - your computer.

For live, you need, ideally, a vocal PA. As was stated above, a distant second choice, but usable alternative would be a keyboard amp with an XLR input.

Could I get some more talent in the monitors, please?

I know it sounds crazy, but try to learn to inhale your voice. www.thebelcantotechnique.com

Chris is the king of relating music things to other objects in real life.