[Samba] Help setting up Samba for the first time Novice user

[Marty]

Hello,

I'm trying to setup Samba. The goal is to have my tow Linux PC's and my 
two Windows PC's connected together on  a LAN. My setup is as follows:

     Router as LAN hub and Internet access,
     Windows 8.1 PC,
     Windows 7 PC,
     Ubuntu 12.04 LTS PC,
     Ubuntu 14.04 LTS PC.

I have installed Sanba 3.6.3 on the 12.04 PC and 4.1.11 on the 14.04. 
Configured the smb.cof on both Linux PC's.
  Have made up the "Shares" and added the users. Shares are in the home 
directory on each PC. User is also the same on each PC. Run testparm on 
both, no problems reported. Some times I see the smbserver when I goto 
the network using Nautalis. I cannot access the Linux PC's.Sometimes I 
see "Failed to retrieve share list from server. I can get to the windows 
PC but not the two Linux PC's. I can ping them however. Searched the net 
and could not find a resolution. Now frustrated and totally confused. 
How can I get this up and running.

Thanks,
Marty