You can browse directly to a share or map to it using the following command from the Command Promt:
-Browse from the command prompt, type:
explorer.exe \\192.168.2.1\sharename (where 192.168.2.1 is the IP address of your PC) or
explorer.exe \\mycomputer\sharename ["\\mycomputer" if you are using DNS; mycomputer denotes the host name]
-Map a drive from command promt, type: net use * \\192.168.2.1\sharename (where 192.168.2.1 is the IP address of your PC) or net use * \\mycomputer\sharename (if you are using DNS; mycomputer is the host name)
With net use, you can supply alternate credentials for connecting to the share using the "/user

OMAIN\jsmith" or "/user:jsmith" switch. If using "/user:jsmith", jsmith will need to have an account on your machine, with permissions to access the share. You can avoid needing credentials by using Simple Sharing. This allows everyone, even those prowlers on the internet (if you machine is on the internet with no protection), to access the shared resources.