type "set" to display a list of all system variables (DATE is a sytem variable!)
use the "@" sign to turn echo off for the current line only
you can use "%n" to pass variables into the batch file (ex: typing "mybat.bat blah crap", then in your bat file you can say
if "%1"=="blah" start blah.exe
if "%2"=="crap" goto crap

here's a little code to get you started:

CODE@ECHO off
CLS
ECHO:This is my batch file
REM enter comments here
IF /i "%1"=="skip" (
ECHO:You must not care what day it is
GOTO endofprogram
)
SET dayofweek=%date:~0,3%
IF "%dayofweek%"=="Fri" (
 ECHO:It's Friday!!
) ELSE (
 ECHO:Nope, not friday yet
)
:endofprogram
ECHO:
ECHO:
PAUSE