There's no real biblical guideline for it, only some examples on how not to fast. But, as someone said before me in this post, there are many ways.
I feel that you being called to, and having a desire to fast is a beautiful thing. Truly it is.
The only fasting that I've really tried, has been a fast from everything except water. Just pray, and be in the word. Don't listen to music, don't watch tv, movies, nothing that your flesh delights in. Only read His word, pray, and fellowship if possible. Obviously you'll be working, or going to school during this time. Your normal life doesn't go on pause, just your entertainment and dietary lives. It's meant to be cleansing, and rewarding. There will be some weird physical signs that happen (irregular heartbeat, momentary dizziness, a euphoric feeling of weightlessness) - ignore them, and trust in Him.
It can, and will be some of the most amazing time you'll spend with Him that you could ever hope to have. There's also fasts that are only from all foods aside from unflavored veggies, there's absolute fasting (no food or water for three days), there's also just fasting for one or two days a week (from everything except water). Generally with the fasting from everything except water, you'll want to try to go as long as you can. Try for a couple days, then keep expanding it out, and work your way up to a week, then two, etc.
Only make sure that your motives are right, and that you are being led into it by Him. Never tell others about your fasting, never. Avoid it entirely if possible. If meals come up, it gets tricky though. I feel as though, as long as you're not trying to brag, or go out of your way to make it known you are fasting or have fasted, then it's fine if it comes up and you're put on the spot with someone wondering why you haven't been eating.