Connecting Linux to a Windows Domain Controller

Please bear with me, I am very new to Networks and Servers.

I see the steps outlined in HowToForge’s Using eBox As Windows Primary Domain Controller](http://www.howtoforge.com/using-ebox-as-windows-primary-domain-controller) and may be trying it out but what I don’t know is how do I make my desktop Linux clients log into the same controller?

I am looking at this at 2 different angles;

  1. Use for my home network so to make it easier to control the different users, permissions, tracking, etc. This includes Linux (Ubuntu, Fedora and openSUSE), Windows XP (laptop) and Windowx 7 (desktop)
  2. Ease of use for somebody I know who is thinking it may be good for one of HIS clients, which likely is going to be a Windows-based network.

Also, are there any special considerations to keep in mind in regards to the laptop logging in and the possibility of the laptop being started outside of the network where there is no access to this server (or, how do I make sure I can log into my laptop when not at home)?

There is no Active Directory component to muck things up, just trying to get a Directory Controller connected using Linux.

Thanks!