Sorry man i searched all over the internet but could only find out that it takes 2.2 quarts (and i am not even sure how veracious that is) but i could not find what weight.
However if you are planning on keeping your quad for a while then it will probably be beneficial to buy a repair manual for it. We have manuals for all of our quads and they can really come in handy when something breaks.
The motor bookstore is the cheapest that i could find but amazon has one to. Your local honda dealer should have one as well.
Honda ATV Repair Manuals: ATC, TRX, Fourtrax, Sportrax, Foreman, Odyssey
Amazon.com: Clymer Manual ATV'S-Honda TRX450 Forman 1998-2004: Automotive
Hopefully somebody else will jump in that has a forman but like i said a repair manual will probably come in handy sooner or later.