We rescued a chihuahua puppy this last winter and it wasn't house broken, and now my carpets stink. Where can I buy a good cleaner to keep it clean?

There are many many good carpet cleaners that will help your carpets stay clean and will take out the odor.
I personally love the Bissel Little Green Carpet cleaner. It keeps the carpets fresh and clean. My mother in law bought me one for Christmas, as she swears by it to get pet odors out of her own carpets. As the mother of a one year old I can tell you this item works great.

Bissell 14007 Little Green Deep Clean Handheld Vacuum Cleaner $70.00

• Compact floor deep cleaner
• Powerful, strong spray and suction removes tough spots and stains
• Effective on both large and small tasks
• Cleans and helps dry in one step
• Long power cord
• Stores ready to use
• Sustainable design and packaging; PVC-free tanks and hose
• All attachments made from 100% recycled plastic
• Model# 14007

Bissell 1719 Spotlifter 2X Portable Deep Cleaner Carpet Cleaner $40.00
Rechargeable/cordless Deluxe brush Spray adjusts Easy fill and empty tanks 12 oz. collection tank 8 oz. solution tank Lightweight Uses Little Green formula, mfg. no. 0499
 

Rug Doctor Oxysteam Carpet Cleaner $18.99

Woolite OXY Deep 2X Pet Stain & Odor Carpet Cleaner 14 oz (397 g) $5.99

Revolutionary Dual Chamber System, 2 Powerful Cleaners activate the power of oxygen with a ... No need to Scrub, Safe for Stain-Resistant Carpet, Clean