Changing or deleting workgroups

I recently changed from Bellsouth Dsl to timewarrner internet and had to get all new routers and wireless stuff.I'm trying to set up my home network again and need a little help. Can i have a network inside my  home wireless? I have 5 computers/laptops .I use a laptop at work and use it a one of my home comp. for work. Cn i setup a privite network/workgroup for these two inside my wireless home? Also One my Dell 5150 the "Workgroup" is "locked " to my old workgroup MCS. How can i change it? Nothing I've tried will work.When i clear MCS the "ok" tab turns clear?? Anyway i can Just remove workgroup altogether? And The Home 5150 is Media 2005/Pro and the laptop is Pro also.Sorry if i ask to many questions. The nearest "Computer Guy" is 30 miles away and they charge a  arm-leg-and name your firstborn after them to come out this far.  Yes i live in Akansas....bfg!