I can't remember which way round I did it [perhaps Richard can clarify], whether to set up the network first then do the sharing bit or the other way round. I suspect the former. Setup the network enables you to access the net from individual computers. Sharing allows you to access other computer members of the network [I call my network 'Home'].
It's also worthwhile searching for other topics connected with networking - there has been a lot of good, plain, simple advice on networking problems that others have experienced, particularly in relation to the use of network wizard [or not]. I seems that it can cause more problems than its worth.
Good luck! And come back to the thread to solve any problems you may have whilst you are setting up...