chrislatta wrote:can anyone tell me how contests work on this site
If I don't fully answer your question you might need to be more specific. Anyways...
First of all, all contest ideas are made up by the staff of the site, this is not the place to post other contests that you (or someone else) made just for fun.
Each contest FBTB hosts is different; there all have similar rules (no unofficial parts, cut stickers, no pre-existing models, etc) but the actual content of the entries will obviously be different.
After the entry deadline the winners are usually chosen by several rounds community voting. Polls are posted and registered members of FBTB get to vote on their favorite build(s). Depending on the number of entries, sometimes there is only one voting round and the winner is chosen based on who got the most votes, or like in this years Mech Madness there are many rounds where builds go head to head against each other and slowly advance through the brackets.
Hope this helps!