If you´re going shopping, I recommend going off the Strip (the Strip is the Street where all the casinos are). There are 2 outlet malls worth visiting:
1) Las Vegas Premium Outlets

It´s on 875 South Grand Central Parkway
This is a great place if you´re looking for cheap brand clothes, shoes, etc.
It´s outdoors, so during the summer I don´t recommend you go there (temperature in Vegas in the summer can reach 110 F)
2) Las Vegas Outlet Center
7400 Las Vegas Boulevard South
This is indoors, so if it´s summer, or raining (it almost never rains in Vegas), I recommend tihs.
Now, if you like glamour, and can spend more $$, then there are lots and lots of options on the Strip:
1) fashion Show Mall
This is the largest shopping on the Strip. It´s fairly new, and features many name brands. Also available are nice restaurants.
2) Forum Shops at Caesars Palace

This is really nice, because the ceiling imitates the sky, so you think you´re outdoors. It could be midnight, and you might have the feeling that ist´s 6pm... it gets darker, then there´s dawn, but it doesn´t correspond to the actual hour of the day/night
There are some nice shops to visit, and there´s always The Cheesecake Factor (see my first entry)
The food court is pretty decent, the cheese pizza is very good, and there´s a sports bar, where you can watch games...
3) Via Bellagio
These are very expensive stores, like Prada, Armani, and Chanel... but it´s worth going just to take a look...
Oh! Forgot to mention earlier, in the Bellagio Casino, there´s a place called the Botanical gardens. You CANNOT miss this. It´s decarated differently throughout the year to reflect the current season. Decoration is made with real flowers, and the smell is just delicious. I usually find the Christmas decorations the most beautiful ones!
Well... I could go on for years talking about Vegas!! I think I covered the main points...
This is in my opinion ine of the most beautiful cities in the World!
Thanks for sticking with me!