Vegas is by far one of my favorite places. It just takes about 6 months to forget about the money I lost and then I'm ready to go back again.
All the advices is great, but one thing from my experience out there. If you plan to gamble, sign up for the reward card and use it at the tables. You probably aren't going to get huge comp points during your stay, but they mail you offers in the mail that aren't too bad for your next trip. Right now I have 3 free nights during the summer at most of the Harrah's properties.
I've stayed at the Flamingo and Ballys several times, and both are nice, and you won't blow huges amounts of money on your rooms.
Oh, and don't gamble alone or at empty tables - your money goes really fast. I made that mistake last trip, when I woke up early (still on east coast time) and headed down to gamble. I ended up several hundred dollars lighter and hadn't even eaten breakfast yet, but I learned an important lesson. Now if I could just learn to walk away from the tables before I give back the gains...