The AA vs Propritary battery seems to be a personal preference and results in long discussions every time its mentioned. I personally prefer AA powered and wouldn't buy anything but. Then there are others who can write paragraphs about why AA's are not good for cameras.

Also be sure to take plenty of pictures, digital space is cheap. And like anything else make backups.

Turn the resolution up all the way. My SIL keeps turning the resolution on my MIL's camera down to 640x480 so she doesn;t have to wait so long for MIL to transfer her pictures over yahoo messenger! So when MIL sends us a picture we get a little postage stamp size that you can't see anything in. You can always reduce a big picture but you can't enlarge a small picture without loss of quality so keep the res high.
Also do not use the Windows XP picture wizard to transfer your pictures, it has bugs and sometimes results in corrupt EXIF data. EXIF data is information on your pictures which records the date, time, etc that the picture was taken. Thanks to EXIF data you also don't need to turn on the silly feature in cameras that printes the date/time on the pictures, its in the EXIF so don't mess up the pics. You will find that there are programs that can read this data from your pictures and sort them by date and time no matter where they reside on your computer and play them back in order. Its kind of fun sometimes to retrace your steps through history and there are also scripts that can take GPS logs and fill in the location in the picture EXIF data and web sites that can display those pictures in their proper location on a map so you can map out your last hike.
Also don't try to rename pictures, eventually you will find that its a pain to try and think if names for thousands of pictures, leave the name alone and edit the EXIF description or commnet fields. You can choose to display those columns in your file explorer or picture organizing program that way your not trying to cram data into a limited file name field and those quick slideshow programs that order the display by file name will still work.