B.,
Are you considering weaning only because he's turning 1, because you're going to school, or because you both are ready? If he's only nursing at nap and bedtime, it may not be necessary to fully wean, and keeping his bedtime nursing routine may be a nice way to reconnect after being away at school for the day. If you've been home with him until now, and you'll be going to school for the day, he may need that reassurance when you return, and weaning may be too many changes at once.
If you are really ready to wean, dropping one nursing session at a time will help ease the transition. Hold him close at naptime, and try just snuggling or offering a bottle or cup of your milk or formula (don't just let him have it in bed- it promotes tooth decay). He will likely fight it, but you'll have to be persistent and understanding about it. After about a week of that, you can drop another session. The nighttime one should be the last to go.
Good luck and good for you for nursing him through his first year!!
H.