Integers and Signed Numbers Worksheet
Use this site for information on integers, absolute values, comparing integers, and adding and subtracting integers. This site allows you to create your own worksheets for these topics.
http://www.edhelper.com/integers.htm

Subtracting Integers
This interactive site is an excellent site for explaining addition.
http://www.berghuis.co.nz/abiator/maths/sa/saintegersub1.html

Adding and Subtracting Integers
This site gives some practice adding on a number line.
http://www.math.com/school/subject1/lessons/S1U1L11DP.html