In reply to Welsh Kate:
I don't know Picassa but a free photo editor which I find easy to use is Photoscape.
It isn't as sophisticated as many of the well known ones - GIMP, Photoshop, etc, but it is VERY easy to use.
Its RAW converter is no good, IMO, but if you are working on .jpegs and you don't need anything too specialised then it is good.
I use GIMP and Photoshop Elements for most of my editiong but if I need to resize, crop or do a few simple things to a .jpeg file then Photoscape often does the job.
Dave