Pros
In my particular office, I have an amazing supervisor--he's positive, helpful, listens to his employees, and is very approachable. I really, really like all the paid federal holidays. Those add up to almost an extra two weeks' paid time off in addition to the accrued annual leave and sick time! So, very good time off benefits. I like the 457 retirement system (it's the equivalent of a 401k but for government workers). My advice is to go to work, be pleasant to everyone, and don't get caught up in the gossipy office culture.
Cons
Whenever there's an empty position to be filled, it takes a VERY long time for the County to get around to testing, interviewing, and then finally filling that position. During that time all the extra work load falls onto the people who are coming to work daily. Medical benefits are expensive. Parking can be tough in down town Fresno, but there is a parking garage you can pay for a couple of blocks away. Yes, you have to pay for it, but they take the payment out of your paycheck pre-tax (that means you end up paying less for it in the long run). There is an extremely negative culture in the County. People complain continually about their jobs. They shouldn't--there's about a 1,000 people out there who would GLADLY take it away from them if they could! The work environment is very clique-ish.