I need help!! My fondant keeps cracking and tearing. it's regluar (store bought) fondant. No coloring or anything... what am i doing wrong???

to much powdered sugar I think. Try wetting your hands a little and work it in to fondant.

What are you doing when it breaks. Are you making bow loops, free standing pieces. If you are making bow loops or free standing pieces make sure you don't roll it to then and make sure it's dry enough to support it's own weight.

i'm making square cakes and it keeps cracking at the edges... it's probably not too cold, since german kitchens don't have airconditioning and we're having a hot summer :S... i might try the shortening thing. wetting hands just makes A HUGE sticky mess!!!

no, don't add water. Add shortening if you have to.

Heres an idea, why not use poured fondant. Its something a lot of people use for pettifors. Its a heated frosting that is poured over your cake squares which will need to be placed on a cooling rack. It dries smooth. Its an excellent way to cover small items with minimal effort. Heres a recipe which is on CC.
http://cakecentral.com/recipes/7449/food-processor-poured-fondant