In reply to BlakeyDerbyshire:
A bit more information might help, what grade range are you interested in and what time of year do you intend to go?
Arco is a great area to climb offering almost every imaginable style of climbing. Sadly, its becoming a victim of its own popularity, some sectors (mostly the famous ones, e.g.
Massone) are polished almost to death, particularly in the lower grades.
However, such is the abundance of crags and the efforts of the locals that there are always newly developed sectors springing up all the time, free from both crowds and polish.
Crags worth a visit:
Val d'Algone
La Gola
Belvedere
But there are many many more! Often overlooked multipitching offers some of the best and most spectacular climbing in the area.
Summer in my opinion is far too hot to climb in, typically 30 plus degrees and mid-afternoon thunderstorms that arrive like clockwork. Spring would be best.
The town itself is classic Italian with a climbers twist, Arco must have the highest density of climbing shops of anywhere (Chamonix included!). Great pizza/restaurants, food generally cheap, supermarkets are decent. Wide range of camping options, though often very pricey, its on lake Garda so expect to pay! Alternatively, there are several sneaky wild camping spots, particularly when you go to the outlying crags.
Transport: can be done without a car, though to get the best out of Arco I'd want one.