As Austin says it is much easier to do on electrics, but if you don't have one have the action (distance between string and fret) lowered as much as possible and putting the lightest gauge strings you can find will help. The guitar shops can do that for you. Otherwise it will be a struggle getting good clean tone. Also take it slow. I would suggest working on them for short durations at a time or you'll experience some hand pain. It's just another one of those things that is gonna take time for your hand to stretch and strengthen to get them to sound right, but once you do your gonna love Barre chords.

Good Luck,

Moe