I set my garage up this year, I put a sink and taps (£5 from ebay) and a long kitchen work surface (very cheap in a sale from a DIY outlet). I was lucky because the garage is next to the house and also had a drain in it, so it was easy to run pipe through the walls and from the sink to the drain, and I just used John guest fittings which is basically like Lego. If it is an option for you, I would highly recommend it.
Honestly, it was the best decision and has made my brew days so simple. I can wash up all my gear in there, water is next to me for filling buckets, boilers and immersion chillers. My kegerator is in there for supping during brew days and there's chairs for people to sit when they visit. I don't use the main garage door so I installed a cooker hood for extraction which works surprisingly well (apart from the odd drip).
I'd suggest a good few coats of tough paint on the floor as well because if you're anything like me you will soak the whole area every time you even look at the tap.