I'm approaching this stage myself and have been doing a lot of finding out about how to do it. Theres loads of info on this site and others.
If you vent to your garage, the whole garage will stink. If you vent to exterior, the area all around your garage will stink. I'm in a situation where I can't vent directly to exterior, because of people walking past my house. Carbon scrubbers are the way forward. I'm a total nOOb here so I'm not sure I'm supposed to link to another forum, but I found this diy carbon filter
DIY- How To - Carbon Filter - CANNABIS.COM Message Boards - Quality Marijuana and Hemp Information with photos and step by step instructions. I'm in the process of making one myself, and I reckon it could be the answer to you smell problem. All the best.