The combination I recommend for amateur usage:
- you need a sturdy monopod (you will typically use it to stabilize a long lens to win a stop or two. The one I recommend for the price/quality ratio is the Manfrotto 682 because of the standalone support.
- you need a good ball-head with a quick-release mechanism - On a monopod I would recommend an hydrostatic head like the 468MGRC2.
More information to be found on http://www.manfrotto.com
There are other excellent manufacturers making monopods: one of the popular ones is Gitzo (top quality, top price too, there is also Velbon (a bit cheaper and lower end but good enough for many amateurs)