don't worry about that, even chinese people can't use these three words correctly every time. As I know, “的”should be more popular. It can be used to link adjective and noun. And if you can't sure which one you could use, "的" is the safest choice. As new Chinese grammar, that's ok. As to “得”and "地”, these two word particularly be used to describe verb. The difference between them is the position. adverb + 地 + verb verb + 得 + adverb.

的 is usually used like this: adjective + 的 + noun For example: 红色的帽子 red hat ..... 红色 is an adjective. It means red. 帽子 is a none. It means hat. 得 is usually used like this: verb + 得 + adverb For example: 干得很好 well done... 干 is a verb. It means do. 很好 is an adverb. It means very well. 地 is usually used like this: adverb + 地 + verb For example: 轻轻地 走 walk lightly.... 轻轻 is an adverb. It means lightly. 走 is a verb. It means walk. Hope this is useful. Good luck!!

I'd like to add some other points.In Chinese,的 is the symbol of attribute, 地 is that of adverbial,and 得 is that of complement. They are usually used like this: 的：adj./n./ pronoun +的＋n. Example 1: as Matt mentioned: 红色的帽子 red hat ( adj.+ 的＋n.) Example 2:鸟儿的翅膀bird's wing (n.+ 的＋n.) Example 3:她的笑容her smile (pronoun +的＋n.) 得：usually the word behind “得” are used to supplement the word before “得”. It is usually used like this: v./adj.+得+adv. Example 1:as Matt mentioned: 干得好　well done(v. +得+adv.) 　　　　　　　　　　　　　飞得高　fly high(v. +得+adv.) Example 2: 黑得可怕 horribly dark （adj.+得+adv.）

i 'd like to tell u a jingle .like this 定“的”， 状“地”，“得”后补。 eg happy means 快乐的 happy is an adj which can be used as attributive to modefy a noun. happy girl 快乐的姑娘 slowly means 慢地 slowly is an adv which can be used as adverbial to modefy a verb walk slowly 慢慢地走 jump for joy means 高兴得跳了起来。 for joy is a phrase which can be used as complement to modefy jump . hope u can catch it .

的+名词：可爱的孩子、灿烂的笑容、美好的生活 得+程度副词or程度形容词：笑得灿烂、跑得快、跳得高 地+动词：狠狠地打、轻轻地放下、慢慢地走来