Travelocity, Expedia, Orbitz, Hotwire, you can check them all for flights, hotels and flight/hotel combos (vacation packages). Most of the airlines also have their own vacation sections on their websites.

Most of the airlines also run "web only" specials that can be quite a bit cheaper than the travel sites.

Sign up to receive email from the airlines that fly to Vegas from your area on a regular basis. It can also be worthwhile to be ready to drive an hour or two to another airport that is served by an airline that has better rates/more flights to Vegas. An example, Frontier regularly has weekend web fares from Denver to Vegas @ $98 round trip, which would make it worth my while to drive the 100 miles to and from DIA.

Many of the Las Vegas casino/hotel websites offer a guaranteed lowest internet rate for their rooms, so booking directly through the casino can also save you some dollars.

If you take some time to do your homework, you should be able to get a pretty good deal.

Have fun!

Bob