Pros
Incredible educational opportunities, regular tech talks and other information sessions. Colleagues are some of the brightest people around. There's also a certain prestige attached with working at Google and you may find your next job easier to get just having had worked there, although the culture makes it such that people straight out of college never want to leave since the perks are so good and they are pampered.
Cons
Lack of proper management, managers don't really care about employees and seem to have just gotten their jobs because they were there rather than showing any competence at actual managing. Competition between workers sometimes strains work-life balance as most are young twenty-somethings with no family to worry about or take care of - although this may change in the future, most older Googlers tend to leave instead of sticking around that environment.
