Thank you so much for all of the help and advice. I really appreciate the pointers on the best place to start.
DixieGal - I had a feeling pdf would be the problem
What can I say, I want the moon on a stick. I totally agree with what you've said and it might well be best to carry a print-out with me. It is the least important feature to me. I'd much rather be able to annotate so I can pick back up on languages again.
My plan so far is to wait for the Neo and the Pocketbook 302 to both come out and see what the hands-on reviews are like. I downloaded Calibre last night and have started to download lots of bits and pieces. Getting some good recommendations from the board here, discovering Smashwords and a few other places in the process. In the meantime might try downloading Stanza for my iPhone and reading from that.
Waiting to purchase my first e-reader is going to be a killer!