I am getting ready to setup a network at home. It will be a router and then 2 (or hopefully 3) computers on DSL. I need to start from scratch as I know nothing about doing this. I need some words of wisdom and some diagrams or explainations on how to set this up.

I will have the main computer downstairs and the router. Then one computer up and another (after we get a moni) in the kids room. Main computer and up have onboard LAN and the one in the kids room has an older LAN card.

Also, what will this do to the d/l and u/l speeds. Is it shared or can I expect to stay about the same as I get now (about 375 down and 150 up)?

Any and all info is welcome, I have only the router coming and have not gotten any of the wiring or outlets. Odie can tell us which router it is, because he is sooo damn good to me.

It will be shared when you are all accessing the net at once, if only one is accessing the net they will get the full speed.

There is almost nothing to do, the Router will dish out internal IP's to the network, with the router picking up the external IP address.

Just a matter of sharing drives / folders.

Shared. on an as needed basis (not a 2-3 way split) if your all just surfing reading the forums etc, it should be unnoticable. If one or more doing a big download from a fast server (say windows update), it could hog most of the bandwidth. it also depends on the router, from the ISP end it's just a bitstream capped at whatever rate you pay for.
As far as wiring buy a roll of cat5 and a crimper (borrow this if you can, a good crimper could be $50. a 12" long 1/4" drill bit (if you can get an electricians bit with a little hole sideway through it , it helps with pulling the wire back) can get almost anywhere with a little planning. for keeping it in the wall (jack to jack( an electricians "wobbly bit" (3-'4' flexible shaft auger bit ($$ for the bit and accessories) works best depending on how finshed looking you want it it can be just a piece Cat5 with crimped ends (buy extra ends in case doesn't look or test out well, or can be snaked through the wall to wall plates and either a purchased ($$) or home made patch cord from the wall to the device. the first is cheap and easy, the second a little more $ and time but looks nicer. each has some advanages.
home depot type store should have everyting you need at a reasonable price, radio shack might do in a pinch.
One consideration is Pulling any extra wire for future use as well as phone line ETC.

The easiest way is getting a 802.11g router and as many 802.11g wireless cards to put in each system.