The & character placed after a Shell command can be used to run the command
in the background and give you a new Shell Prompt so you can continue
working.
You will notice aliases in .cshrc for some of the ls commands (they are
very convenient). You can create other aliases by editing .cshrc.
An excellent book that explains Unix commands and utilities is Abrahams &
Larson, Unix for the Impatient (2nd ed., Addison-Wesley, 1996). There is
also a lot of Unix information on the Internet. Try the Unix Reference
Desk.