Windows 7 isn't any different with regard to networking. It's exactly the same for years and years. There is Homegroup but we are not considering that.
When you map a drive, you have the option to set different credentials (user/pass of remote machine you're connecting to.) You can choose to have Windows remember these credentials and you could also have Windows remap with these credentials upon every boot.
Same user/pass on each machine not necessary, but if they are same, Windows will never ask and just grant permission.
Open Windows explorer | click map network drive
There are two check boxes describing the actions available as I've described.
When you're sharing a folder from a machine, to make it simple as possible, grant everyone permission by actually typing out everyone.
In Windows Explorer, it's a good idea to click organize, folder and search options, view tab. Scroll to bottom. Uncheck the box for "Use Sharing Wizard (Recommended)"
Further info: All attached HDD are automatically shared with a $ after their drive letter. $ makes them hidden on network and not viewable in network maps.
So C: is shared as C$, D: as D$
Command prompt, type net share
, hit enter to see your shares from any machine.
A good security measure is to make sure your router does not allow incoming netbios ports 137-139 or 445 from outside internet.
Passwords on account must be set and not non-existant. If they don't exist, you are not going to share. It's a built-in security measure.
Another good measure is to enter line in hosts file for each machine on network and set static ips. C:\Windows\System32\Drivers
If ComputerA has static ip 192.168.0.30
ComputerB has static ip 192.168.0.31
enter a lines as:
Enter line for each machine. Save hosts. Go to your other pcs and do the same for the remote machines to it.
If anyone has any questions regarding any of this, please feel free to speak up.