Hi Gabe, first and foremost, welcome to the forums.
Said that, let me explain something to you
SNC, Saturday Night Contests are not something you sign up for, they are toll free contest given to us by theory11 artists every saturday night (because of their good hearts

).
These contests vary from thousands of different ideas, ideas you can improve by posting
here. Moving on, If the contest involves a video of some sort - you will see that it mentions you should upload you video to any major video sharing website (youtube, vimeo, metacafe, revver...). Then, once you're sure it has browsed and been accepted into this website, you can post a link to it on the SNC official thread (made every saturday night in acordance to the contest).
Prizes can vary from decks, to signed uncut sheets of playing cards, to 1on1's - even to Wayne Houchins, if you're special. Or very lucky. Or if your name is Dana.
Anywho, hope I've answered you question!
Don't hesitate to PM me, Doug (Sinful), Jack the Magician, Rebelace69, KatieEgelston, any of the theory11 artists, and mistah Raiker. Jon Raiker.
And Dr. Bayme, PhD in Astrophysicofbeingaweosme.
Gustav
EDIT: I forgot to mention that you probably haven't seen these contests yet because you live in Hungary. Unfortunately, one day when Wayne Houcheewoochee had a bad hair day, he created time zones, thereby definitively reducing the amount of people he has to reward with prizes from SNC's.
That's my theory, anyways.
I live in Norway, and here - for me to be in time for an SNC, I have to stay awake until 3am on a Saturday/Sunday. Not very nice.
In the US, the time they come out is 11pm Eastern Standard Time - probably one of the more annoying things ever, if you ask me
Alas, nothing yo ucan do about it. Except stay awake, that is.