tools for security

[SLEE]

hi all i want to do some security testing on a site but what tools are available?
I want to be able to read cookies easily have teh ability to edit them if necessary to check if i change something will it let me login etc.
I would liek to be able to test that the ssl cert is installed properly so a way of tracking the infomation being sent from the site would be good too.

just a note im not trying to hack a site this is purely to check our security. we have had securoty test which let us know some holes and i have implemented afew changes and id liek to be able to test them.

thanks