Sharepoint is really good for this kind of function.
You can create 'lists' which are effectively database tables that you can then link together. I created a complete CRM solution in Sharepoint 2007 (WSS v3.0 - the free version) quite quickly.
Just sit down and figure out what information you need ie
and how they might relate to each other.
Also do a search for "Sharepoint Fantastic 40" templates. there might be something that you can use.
Compuserve->AOL->Virgin->Tiscali->Sky->Plusnet->TalkTalk (3 weeks)->Plusnet->Sky->Soon to be Plusnet Fibre