I swear by GooGone. If you have a really tough "sticky", try GooGone and use a plastic net scrubber to help remove gunk (gently). I've also had luck with plain cooking oil to remove labels.
You can find GooGone almost anywhere, including grocery stores. K-Mart, WalMart guaranteed to have it as would hardwares.
Good Luck! :approve:
A while back i found this british labels company, i ordered some plain labels from them as their prices were so low. Just thought it may interest you to know that they also had a page on their website with tips for removing sticky labels so it may be worth taking a look.