The thing I found easiest when lab hunting, was to go to the website of whichever department I wanted to work with and then to browse the professors' research profiles. Once I found a few people doing work that sounded interesting to me, I shot off a few emails introducing myself, explaining that I was looking for a research lab, and asking if I could get together with them to talk about their research.
Most of the professors I spoke to were more than interested in discussing their work with me - and they were thrilled to take on a student as long as they didn't have to pay. If you want a paid position, it is usually easier to look for a lab position through the university career center or via job postings online. Just keep in mind that some positions that will pay you require you to already have an undergraduate degree, and the ones you would be qualified for are generally very bland work (doing dishes, making solutions, etc).
