login plugin

Hi,

I m trying to put a login form in my wordpress.
I have install 2 plugins :
the sidebar Login 2.2.5
and the AJAX login 1.0

None of these appear in my website when I activate them.
Do I have to do something else? Do they appear somewhere
where I can’t see them?

And if finally solve this and make it appear in the webpage,
would it be possible to change its position in the website if
I dont like the one that appears?