What are the differences between 的,地 and 得? I am trying to understand the differences between the three (de) in Chinese.
let me answer the question you asked:
Firstly, I assume you are an English speaker.
的,地 and 得 are three very basic linking words in Chinese.



'的' is used follows attributes which are the adjectives you called.
For instance:
In English: She  is   a   lovely  girl.
In Chinese:  她  是  一位  漂亮的  女孩。
So, you can notice that 'lovely' substituted by '漂亮的' in Chinese.



'地' is used follows attributes as adverbs.
For instance:
In English: He drives carefully.
In Chinese:他 小心地 开车。
The 'carefully' is replaced by '小心地'



'得' often express the meaning of degree and possibility.  It is very complex to use and even the native speaker can make a fault. 

Considering you are a learner, I recommend you to memorize this structure:
verb + 得 + a sentence
in the structure above, 得 is very similar to 'so that'
For instance:
English:I'm    so tired that     I can't walk anymore.
Chinese: 我    累得               走不动路了
It linked the relationship between 'can't walk anymore' and 'tired'.  

It can also express the possibility:
English:The floor needs    mopping.
Chinese:地板      得       拖了
In another word, 得 can replace 'need' and this a very idiomatic Chinese phraseology. I highly recommend you to replace '需要' terms of '得' in oral Chinese.  



If you keep any questions, just ask. I'm very glad to help you.