楽しい is fun, something enjoyable うれしい is happy For example, a game can be 楽しい, but hardly うれしい. In the same way, if something good happens to you, you can feel うれしい, but it's weird to feel 楽しい. がんばってください！

嬉しい「うれしい」In comparison of 楽しい「たのしい」is used for more prolonged happy times... like... For example: If you meet your favourite pop star, you say 嬉しい If you open a gift, you say 楽しい Because you are happy for more time with a pop star than opening a gift. 分かった？

Why not try this video on the difference 　between　うれしい／たのしい／かなしい. all Japanese, but simple to understand. http://www.youtube.com/watch?v=nBliT1xdB-4