Place to start? here
I assume you have a Codex, you next step may be to make an army list detailing what nodels you will use on the field of battle. Try to make the list using the models you have.
Some standard point sizes.
400 combat patrol(no heavy tanks, no super units, don't need to use 1hq 2 troops....great for starting with a limited model count)
500(with or without combat patrol rules.
750 (normal rules.. makes for a fast game that still lets you use diffrent parts of your armies, tanks start to show up as well as awsome creatures.)
1000(almost a full game)
1500(standard game
1750 (because not everything you wanted fit into 1500)
So make your army lists for what ever point you think you can make with your models. Then assemble the units you need and start painting them. Can start playing.
From there plan your next lists and grow as needed.
For the lists post them here and we can offer advice on them.
yeah, i got the codex'es, friend put them onto a DVD for me (he has nearly all of them in book form, missing Witch hunters and wargear.)
As for the points thing, i havn't quite got that far. it was mostly walk into a shop, buy some guys, assemble them, paint them. and that's about as far as i got. i'll read the codex'es at work.
Space Marine Tactical Squad x2
Space Marine Commander
Space Marine Assault Squad
Lt varras
Brother Whatsaface.
there is also some of the alien ones (my brain has totally failed, its nearly 4am.) because i got the 'Battle for Macragge' pack (and then extra tactical/assault/commander seperate.) so i'm not sure what that would rank out point-wise.
hope that info helps out about what i have (for a few weeks anyway, finish paying off some things next week and i'll grab some more SM's
p.s- sorry for double posting