Does your guitar have a high-gloss finish or a satin oil finish?
If your guitar's finish is high-gloss, you can rarely go wrong with lighter fluid. I've removed stickers from all kinds of stuff (wood, hardback book covers, plastic DVD packages, etc.), and I've never had a problem with lighter fluid discoloring or eating into a finish. As with everything, though, it's best to test first in an inconspicuous area.
Starting with one sticker, use a few drops of lighter fluid until the sticker is saturated. After letting it soak for a bit, gently peel the sticker back. Using this method will take a while, and will probably require you to remove the leftover residue under each sticker. (It depends on how long the stickers have been on your acoustic.) Just be patient and work with one small area at a time.
Keep plenty of paper towels on hand, and be sure to buy some that are entirely white. Sometimes, paper towels are printed with inks that can run or smear when subjected to solvents.
If you have an oil finish, check with a furniture/paint store before you do anything. Since oil finishes usually leave some of the woodgrain exposed, chances are that your stickers have made more contact with the guitar. Also, oil finishes are typically thinner than gloss finishes... and there's a small chance that lighter fluid could eat into the finish.
Finally, do not try "Goo Gone" or "Oops" unless you're fearless of heart! Both of those products contain a powerful agent called napthalene, and chances are that you'll cloud up or eat into whatever finish is on your guitar. Rubbing alcohol can sometimes work on stickers, but it dries quickly and can leave "fog" spots. Lighter fluid is your best bet!