New to GIS, can you help?

Hi, I live on an island off the Northumberland coast of England and am in the process of trying to set up a GIS record of the flora/ fauna reports being generated. I've done a fair bit of reading on the subject and although I now understand most of the underlying concepts there are a few things I'm having difficulty with. Can anyone recommend a good freeware GIS program for a beginner? Also, I could really do with incorporating aerial photography or a satellite image as a background raster to get the ball rolling. Any suggestions on where I can get this? Thanks a million :)