Rebecca,
What 5 things do you want to do most,other than re-sizing?
Picasa is good too and will almost everything that needs to be done, on a basic level. I don't use Picasa, but I think that it's a first level kinda program and then GIMP goes up from there. Photoshop Elements 12,which costs anywhere from $50-$70, is more of a complete program and something most photographers use all the time and has no limits for them and their artwork. PSE 12, also takes some learning, but the videos on Youtube are extensive,both from Adobe and also from others that teach the "how to's". The nice thing about PSE 12, is that once you learn it, you're ready to jump up to the full Photoshop version,since all the tools and functions will be there and then a few new ones.
So, it really depends on what you want and need to do,
RIch