Free software - I'd recommend Paint.Net (http://www.getpaint.net) for basic photo work. It's a very good package, as good as Paint Shop Pro but without the cost involved.

Pay software - If you already have a package, look into Adobe Photoshop Lightroom. It's a very good package tool that'll let you do a lot of manipulation of photographs without needing Photoshop or any other packages (although it does integrate into them nicely).