The majority of feminine nouns end in 'e'. Although there are exceptions.

The ending sound of the word will help you to recongnise them, but be aware that there are a lot of exeptions.No rule is 100% foolproof in French. Some website uses a lot of categories to sort words (like this website http://french.about.com/od/grammar/a/genderpatterns.htm ) but I think this is too much to be learnable ! It's better to sort words in just about 10 common endings (like words finishing with the sound "o" - regardless of the spelling - are usually masculine) and then just learn as you go. There is enough material with this subject to fill near an hour !

A feminine noun is preceded by 'la' and a masculine noun is preceded by 'le' in French.