Questions about Hardware upgrades

I've had my macbook pro for a little more than a year now. It is my first mac and I am very happy with it, I've slowly been starting to do all my work on my mac and only using my PC for games.

Unfortunately my PC is in the process of dying a slow death. Rather than dump more money into it I thought it might be a better idea to upgrade my mbp and go with a bootcamp or parallels solution.

Since I am still relatively new to macs I had some questions. I know the new imacs are not upgradeable, does the same apply to my mbp? I bought it at the end of 2008. I wouldn't think so because it is a laptop and I see there should be access to some things from the bottom as on normal laptops. I did want to ask to make sure.

Another question is how different is it to upgrade the hardware than on a windows laptop. My husband is very comfortable with computers and is a network admin, however he lives in a windows world and I think my mbp scares him a little bit lol. Would he be fine doing the upgrades on my mbp if he is 100% comfortable on any other manufacturer?

Also the things I wanted to upgrade were the memory and the hdd. I only have 300 gigs and with the work I do, a lot of graphic design work, that space gets eaten up quick so I don't really have space for a windows partition. What is the best place to acquire these items for an mpb?

Lastly! Is it possible for me to completely retain my applications as well as my data? I have backups but I am not really familiar with all the mac is capable of in that area. Exactly how much work can I expect in regards to reinstalling anything.

Thanks in advance!
Bre