I currently have seven Dell PCs running Windows XP Home Edition. They are configured as follows:

Pentium 4 at 3.0 GHz
100-GB IDE hard drive
512 MB of memory, floppy drive
CD-ROM
64MB memory video card
1 parallel port, 1 serial port, and 1 USB 2.0 port
What type of network architecture/model and topology would you recommend, and why?

Connect them to your router, either wirelessly or wired.

You would use a star topography connecting each computer to central switch or SOHO router with a built in switch. An additional connection would run from the switch to the head in device or Cable/DSL Modem. Sounds like a question from a networking 101 class if so check out the following.
http://www.techiwarehouse.com/cms/engine.php?page_id=d9e99072
http://compnetworking.about.com/od/basicnetworkingconcepts/Networking_Basics_Key_Concepts_in_Computer_Network ing.htmhttp://compnetworking.about.com/od/basicnetworkingconcepts/Networking_Basics_Key_Concepts_in_Computer_Network ing.htm
http://www.techsupportforum.com/forums/f58/helpful-sites-for-learning-basic-networking-3374.htmlhttp://www.techsupportforum.com/forums/f58/helpful-sites-for-learning-basic-networking-3374.html