I bought the RS France 2012 but there is no mention of Nimes. In other books this city is highlighted for its many Roman artifacts/sights. Is this a good way to spend a day? We are staying in Avignon for 4 days.
We visited Nimes in 2007 and really enjoyed it. There are a few really nice Roman ruins in very good condition, and the town itself is very pleasant. We passed a good hour or so in the park. We had the RS Provence book and it was mentioned in there; maybe see if your library has it or check on the Amazon search inside feature to see if you can get the pages you need easily. It did include information on the ruins there, so if your other books don't go into much detail, it might be worth it. We did have a bear of a time getting out of the city, so if you are driving, beware of the roundabouts as you exit the city! They tend to send you back and forth. :)
You want purchase RS Provence & the French Riviera; it covers Nimes.
He also shows Nîmes on his episode "Provence: Legendary Light, Wind, and Wine".
Spent a week in Nimes a few years ago and enjoyed it. Definitely worth spending a day there. Great Roman ruins.