Well. The answer to the first question is irrelvant if your intent is to actually make your own sword. Basically if you have to ask the question you're a pretty hopeless case. Still if you are looking for purely curiosity reasons, I'd suggest a couple of things. First go to google and find Richard Stein's Japanese Sword Index. More info than you can shake a stick at. The second would be to join SwordForum International( http://www.swordforum.com
). They have a forum dedicated to sword smiths.
As to your second question, yes you can go to Japan and buy traditionally forged swords. It isn't really necessary, but it's the best way if you can manage it. You can also order swords directly through a handful of vendors that import them. The only one I know of is http://www.swordstore.com
Get ready for a hefty bill however. They'll set you back something along the lines of $5000 or so at a minimum.