First, I am a bit puzzeld about the IP addresses. LAN IP addresses should be non-routeable ones and you are using static routeable ones. I suspect this has a lot to do with your problems.
The router WAN port should be set for a dyanmic public IP address if you have a dynanamic IP address from your ISP. If you have a static IP address (and subnet mask, default gateway, and DNS addresses as well) provided by your ISP, then you configure the WAN port of the router for a static public IP address and enter these addresses in their respective places.
The router LAN or Private IP addresses are different. Usually for home grade routers, they are defaulted to a 192.168.0.0 /24 or 192.168.1.1 / 24 subnet. Most of the time the router address will be 192.168.0.1 or 192.168.1.1 as your router manual directs. These are non-routeable IP addresses which you want on the LAN side. You can allow the router to assign LAN IP addresses via Dynamic Host Configuration Protocol (DHCP) as well which means you do not need to assign static IP addresses to LAN pcs. I suggest you do this. I recommend that you reset your router as directed by your router manual and set up this way.
Now, once this is done and from each pc you can ping the default gateway (router actually) successfully and access the Internet, let's focus on sharing files among LAN pcs.
Let's say you have 2 pcs (the actual number is not critical but I am trying to make a simple example), called pc A and pc B. Let's say you wish to access a directory (folder) along with its subdirectories (subfolders) in pc A, c directory, called "data" by pc B. From pc A, open Windows Explorer, right click on the c:\Data directory and click on the sharing option and follow prompts and invoke sharing for subdirectories as weall.
Now from pc B, with windows explorer, map a network drive (Tools, map a network drive) to pcA, c:\data directory drive, and check the reconnect at log on box). You may be prompted to provide a user name and password for pc A; if so fill it in.
Now you should be able to see c:\data of pcA in windows explorer of pcB. You can even put a short cut on desktop of pcB from pcB Windows Explorer to link to c:\data of pcA if you want.