Cyber Monday with $50 Credit

Hi everyone, been lurking for a few months here and learned a lot so far. Tried the quickhits thing last trip but failed miserably. Getting ready for the next trip, and wanted to try Caesars. Had a couple questions though.

1) I found a Cyber Monday promo on www.mycheapvegas.com that gives $50 credit. Is this site legit or will I get some kind of virus going through their links?

2) I'm looking to go 4 nights. Can I book 2 separate reservations to get $100 in credit instead?

3) How do I use these credits?

Thanks everyone in advance!