Reading a book in the same genre as your book is the best way to get an idea.
A prime example of how to do scenery descriptions well, can be read in any Stephen King book. That guy rights some very detailed descriptions.
Essentially, you got to work with two main senses. Eyesight and hearing. Sometimes, touch and smell when necessary. It should also try to evoke an emotional response from the narrator or character(s).
Of course, I wouldn't worry about this too much, until your finished your rough draft. Also, I don't recommend letting people read an unfinished manuscript.
Finish your rough draft first. Once done, you can fix descriptions and any other errors. Then, let proofreaders and editors go over that draft to find errors missed.