Part 1:
I stumbled upon some really nice Linux Command Refrences. Enjoy!

http://www.oreillynet.com/linux/cmd/
http://www.linuxnewbie.org/nhf/intel/commands/
http://education.vsnl.com/cyberciti/linuxcom.htm

If you need a better Reference, PM me and I can send you a really good ebook.

Part 2:
I'm very sure that there are some people here who have a real hard time adjusting to Linux, but if you use MS-DOS, here is a nice comparisson between MS-DOS commands and their Unix equivalents. (Please note that this is from a book called 'Unix for the Impatient').

MS-DOS | Unix
attrib |chmod, ls -l
cd, chdir |cd, cddir, pwd
command |sh, csh
comp |cmp
copy |cp, cat
date |date
del, erase |rm
dir |ls
exit |exit
fc |cmp, diff
find |fgrep
md,mkdir |mkdir
more |more, less, pg
path |set PATH
print |lp,lpr
prompt |set PS1, set prompt
rem |echo
ren |mv
rd, rmdir |rmdir, rm -r
set |set, setenv
sort |sort
time |date
type |cat
xcopy |cp, cpio -p

**Please remember that the above "Ms-DOS commands and their Unix Equivalents" is a exerpt from "UNIX for the Impatient" which is an excellent book if you want to learn UNIX quick.