How do you create a signature and change font settings for group posts?

I would like to set a default signature and font setting for the posts that I post onto the groups that I belong. I am totally web based and don't email to the group... I use the group ';Post'; function but can't seem to find an easy way to add a signature or change my default posting font to anything other than courier. Thanks.How do you create a signature and change font settings for group posts?
when posting on the group, you'll have to copy and paste a signature each time. signatures are an e-mail feature and posting off the group wont save such a thing nor does it have that feature.

as for font setting, when posting you'll see



New! Compose your message with Rich-Text Editor %26lt;-- click- next page you'll see where you can change the font, text sixe and color.