My team is building a forklift and we’re having trouble with the design of the forklift.
We will be more then happy if someone could send us any documents or sketches of forklift. 
I haven’t designed a forklift before, but Adam Heard has a video about the design of an elevator that I found helpful:
Here
And he also has a video about setting up some of the calculations for an elevator:
Here
These videos, and all of the others, that Adam Heard has done are great resources.
I also recommend taking a look at this thread. There are several links inside that go to white papers, photo galleries, CAD files, etc.
A few things that might assist you:
-Team 254’s 2011 build blog
-Photos of lifts I have compiled
-Patrick Fairbank’s 2011 Championship photos (there are a few good lift photos)
It depends on what you’re trying to accomplish.
How much do you want to carry? How high do you want it to go? Does it need to collapse down to a low height? How fast must it go?