How to give commands to Linux

[Manisha <manisha aurica com>]

I am totally new to Linux. I want to give write permission to one directory 
- want to create and write into the file - I can open the directory (like 
explorer in  windows), but then how to give  the write permission ?

Can anybody explain in detail the steps involved? I am sorry to ask such a 
silly question, but...

Thanks in advance
Manisha