Can anyone tell me if it is possible to block a website or ip address from an ASA 5505? if it is possible, can you give me an example of the commands to get it done?
Assuming that your traffic is from the ASA inside interface towards the outside interface, and assuming that you have no access-list applied to the inside interface at the moment:
To block to a specific website:
access-list inside-acl deny tcp any host eq 80
access-list inside-acl permit ip any any
access-group inside-acl in interface inside
If you however already have an access-list applied to your inside interface, just add the deny statement above all the permit statement to block the access.
Hope that helps.