Hi

I am currently planning a site that allows members to vote on designs

There will also need to be a time limit for each contest for example one month.

And the Admin of the site will should be able to easily review entries and approve or delete/disapprove the entries - entries will contain title, description, thumb and main image

Any advice on how to proceed?

Here are 2 example site that have the voting functionality:
http://www.designbyhumans.com/vote
http://www.threadless.com/submission/291461/King_of_the_Jungle

thanks!