Ok so I have a fairly simple question (I hope).

How do I setup my Windows 7 network....and this is the key word >>>Efficiantly<<<

Problems I have had before:
Xp Machines unable to connect to Windows 7 machines
Machines with no password asking for passwords
Machines not showing up on "My network Places"

Things You should Know:
Running a router I got from my ISP
Using a 10.0.0.0/24 network(router's default topology)
Mostly Using ESET 4 Smart Security and Avast Antivirus
Gaming(meaning I have friends coming over to lan)

Things I would like to Know
How to set up network security(Using Windows 7 and ESET settings)
Setting up and managing Network access Usernames and Passwords
Any other useful stuffs you think I would want to know

Keep in mind I am studying in this general direction, so you can throw them acronyms at me or get technical, the more advanced the better

TeeWhy