Yes, the RJ45 lan socket is the standard network socket that you attach the Virgin modem to.
Outlook Express is part of my Windows XP software; I'm assuming it's also part of Vista so you'll have it by default.
(As far as I know, MSWorks is just a very much cut down version of MS Office)
802 11N is just the wireless standard which they keep improving. They still haven't finalised N hence the 'draft', but it's the latest and best.