Congrats on your new acquisition!

I found these pages very helpful:
http://www.hisremnant.org/Vuitton/care.html
http://www.hisremnant.org/Vuitton/patina.html
I'd recommend a leather protectant for the handles of your Speedy, so that it'll develop a nice, even patina rather than the chocolate brown that results from absorbing the oils in your hand. (Unless you like the chocolate brown patina, of course!)
I've used Wilson's Suede and Leather Protectant for my
Coach bags and it worked quite well, but I hear that Shining Monkey works wonders. While I can't give you my personal review of it yet - I just ordered a can a few days ago - I think there are other members here who would vouch for it. You can order it from here:
http://www.shiningmonkey.com/fabricprotect.php
Also are the LVs not waterproof?????
Unfortunately, Monogram isn't ideal for rainy days because the vachetta leather is so vulnerable to moisture (and dirt). There's really no way to clean it once it's marred...just hope that the patina will camouflage the stain well. At least if it gets really bad you can get the handles replaced for $175.
Damier Canvas is water resistant, and resistant to the elements in general (e.g. it won't oxidize) but the chocolate brown leather trim is prone to scratches.
I don't own any Epi, Vernis, or other pieces (yet!) so I'm not sure how those fare.