I've got to 2nd/3rd/4th the corncob pipes. They are great for starters. If you want briar though, I highly suggest a Savinelli natural. They are Savs that didn't pass the "pretty inspection" (ie have minor flaws in the grain or something like that). Frenchy (frenchyspipes.com) is having a sell on Savs right now. He's got a Lucite natural #9 for $30 bucks. I've got the Lucite #6 from him and LOVE it!
For figuring out what tobacco you like though, is where the corncob comes in. You don't want to smoke different types of tobacco in the briar. For instance, you want different briars for aromatics, english/orientals, virginias, virginia/perique blends and so forth. Some even smoke only one blend in a certain pipe. For each of those, there's plenty of threads on here giving great suggestions.
Here's one:
http://www.clubstogie.com/vb/showthread.php?t=148952
But my recommendations
English--Frog morton to start (or Squadron leader). Both are smooth and have the traditional english feel.
Va--full virginia flake (only real virginia I've smoked)
Va/Per--escudo, or PS luxury navy flake (there's a whole thread comparing Va/Per blends--search for Va/Per showdown)
Aromatics--whatever you think smells good (I typically stay away from aromatics, but those may be your favorites; don't know until you try).