Speaking of ebooks, I've been reading the Honor Harrington series by David Weber. It has been described as Hornblower in space and I can't agree more.
It is great fun.
The books are published by Baen Books, who have a history of releasing ebooks for free around the place. As a result, you are able to get most if not all of the series off promotional CD-ROMS that have been released over the place have been placed on the bittorrent network.
"On Basilisk Station", the first in the series, is on the "War of Honor" CD if you don't want to download them all first!
I can also recommend Eric Flint's "1632" and John Ringo's "A Hymn Before Battle", also on that same CD.