What sort of a resulting configuration or environment are you seeking?
If you're looking to have your Windows clients access storage on your OS X Server and to not authenticate with your OS X Server system, then you can dispense with some of the configuration steps.
However if you're looking to have the same login everywhere (Windows and OS X), then requirements become somewhat more complex.
And which version(s) of Windows? Particularly if you have Windows 7, the options and requirements differ.
It's less common to have Windows configured to authenticate to OS X; it's more common to use Windows Server and its Activie Directory, either in isolation or in combination with an OS X Server in what's called a "magic triangle" configuration. Alternatively (if you do want to set up this direct authentication of Windows and OS X Server and Open Directory), then see Mac OS X Server: Alternatives to Windows NT 4.0 domain control (PDC) technology (HT4945); that uses pGina.
And before you proceed here with any work involving authentication, delegation or related tasks, launch Terminal.app from Applications > Utilities folder, and issue the following non-destructive command to verify your DNS is correct:
sudo changeip -checkhostname
You'll need to specify an administrative password when prompted. Proper local DNS services are central to getting any of this stuff to work, and this command will (non-destructively) indicate if DNS is correct or if there are issues or changes needed.
The OS X Server 10.6 documentation is available from Apple, and that can help provide you with some background in this topic. The 10.6 intro, 10.6 User Management, and 10.6 Open Directory would likely be worth downloading and skimming. Probably also 10.6 File Services, if that's part of your goal. (Running a server isn't quite as no-IT-required as might be hoped, unfortunately. And I don't know of a short cookbook for this stuff; the steps and configurations can vary, depending on your local requirements - apologies on pointing to the docs here.)