Lol dude, try actually reading it.
It's a **** fine guide, and it's only listed as a faq.
try reading past the table of contents.
you asked where to start with marth, the guide does a good job of explaining how all of his moves work; which move does what, and what situations they're good in.
it covers a lot of marth's essential playing styles as well.
I'll tell you this:
If you've been playing for a while, hopefully your are good at wavedashing. Get used to the timing of marth's wd, and try to dashdance and waveland naturally. Go to BF or FoD and try to fluidly jump and slide around the stage on it's platforms.
If you can move quickly and sporadically around the stage, it'll really help the fact that you have no projectile. Combined with JC Grabs, and your defensive game will be of to a nice start (marth's speed, especially when wavelanding, combined with his great grab range make it easy to punish whiffs and interupt attacks).
Try and learn the spacing of his tipped attacks, mainly the fmash, all 3 tilts, fair, dair, bair, and uair.
a tipped ledgehopped (or ledgedropped) bair is a great way to edgegaurd those coming from below (like other marths). also, waiting for a spaced fsmash/dtilt can encourage other characters to try and sweetspot, and that sometimes allows you the time to dash->reverse WD into an edgehog. (but that's getting into mind games. take some time to get used to marth.)
learn to sweetspot his up b, and try and learn the timing of his up throw chain grab.
and read that guide, trust me.
JDZL
Anyhting will help, im going to watch some Marth videos right now.