1.dir will display the contents of your current folder.
If there is too much to fit on the screen at once, use dir /p to go through the contents one page at a time.
2.cd FOLDERNAME (or chdir FOLDERNAME) will access the specified folder. Note that you can only access files or other folders that are within your current folder.
Example: If you are at C:\ and you want to access C:\BIGFOLDER\TARGETFOLDER\
-Enter cd BIGFOLDER to get to C:\BIGFOLDER\
-Now enter cd TARGETFOLDER to get to C:\BIGFOLDER\TARGETFOLDER\
3.cd.. will move you up one folder.
Example: If you are at C:\BIGFOLDER\TARGETFOLDER\
-Enter cd.. to bring you up to C:\BIGFOLDER\
4.cd\ will bring you back to the root directory regardless of what folder you are currently in.
Example: If you are at C:\BIGFOLDER\TARGETFOLDER\
-Enter cd\ to bring you back to C:\