Is it OK to post books for sale here?

Each group is different and I don't want to break any netiquet, so
I've got a few questions since I couldn't find a faq for this group:

Is it appropriate to post books for sale in this group? What about
other technical stuff like software and hardware? I ask this knowing
that there are a lot of posts already doing that in this group, but
I've seen other groups where people routinely break the rules. I
don't plan on being one of those people. If it's frowned upon, I
won't do it. I do have some of my old books and stuff for sale, but
I'll wait first to hear if it's appropriate from you guys.

If it *is* appropriate, is it OK to list one book per post, giving
some detail on the book, rather than a bunch of one liners in a single
post? Which is preferred, or does it matter? I've just finished up
making my own personal website where I've got my used books for sale
on it. Is it appropriate to provide a link to the book(s) on my site?

I realize it may seem odd to ask this, since most people just do it,
but it's really important to me that I comply with the wishes of the
people that use this group.

Thanks!