I have IE8. I have it set to ask me if I want to save a password. I must have said no on a few sites, but I now want it to save for those sites. Can I change it to now save for those sites?

I'm not sure if you mean for one specific site or for all sites. But I'll make an assumption that you are not being prompted to save passwords for any sites.

To correct that you need to click Tools -> Internet Options -> Content -> AutoComplete Settings. Then check the "Ask me before saving passwords" and make sure that the "User names and passwords on forms" is also checked.