Kilroy that only works if the administrator account is enabled. Nowdays on decentralized networks the admin account is disabled. There are several things you need to do.
First off you need to turn off password protected sharing under the advanced sharing setting under the network sharing center. In the cortana box type control panel which will open the old win 7 style control panel. Click network and sharing center, then on the left click advanced sharing settings. Expand the Home or Work settings and set these items accordingly on all the computers.
1. Turn on Network Discovery
2. Turn on File and Print Sharing
3. Turn off password protected sharing
Next we want to enable the Administrator account and enable blank passwords. In the cortana box type gpedit.msc and hit enter. Under computer configuration \ Windows Settings \ Local Policies \ Security Options make these changes.
1. Accounts: Administrator account status Enabled.
2. Accounts: Limit local account use blank passwords to console logon only Disabled.
Now you need to create the shares on the systems that need it. Navigate to the folder you want shared, right click on it and select Share With -> Selected people. Click the drop down and select Everyone. Change the Everyone users rights to Read and Write. Now you can do as Kilroy says and use the net use command but it would be a little different.
net use x: \\computername\sharename
Thats all you need. Another way which might be easier for you is to open the file explorer and browse the network for the computer you want to gain access to its share. Click on the Computer then right click on the folder you want map and select Map Network Drive. The rest is easy step by set stuff. When the mapping is done, test it by adding a file to the share and then deleting it.