I'm not a wahm, but I have a question about shipping info having run a couple of co-ops. I ship priority and use the USPS site for postage. From there it lets me send the receiver an email with the DC number. Is that satisfactory? I tend to also post on the yahoogroup when packages are sent, but I don't email people individually besides (other than those who have had big orders that went thru Airborne since I had to manually send them a tracking number).
My thoughts on WAHM business:
*I'm gonna agree with Meg that freebies are nice but not necessary.
*If my package is late/you forgot about me/whatever is holding it up: Do NOT delay my package more by adding free stuff to it (the "oh I'm so sorry, I'll give you another diaper for free" that ends up adding ANOTHER week to my already late package).
*I don't expect chit chatty emails. They're nice, but I'm okay with just a polite note. So don't feel you need to set aside hours for me

Just "thanks for your order, your total is XXX. " is fine.
*Gimme business cards. Throw in at least 2. I file them, and sometimes I carry a couple for things I LOVE in case someone asks.

*I think a reasonable shipping estimate should be posted on your site ("we ship instock within 72 hours").
*I think it is reasonable that you have "business hours." But for those of us who sometimes forget that wahms aren't sitting on their hands waiting on my business, you could mention on your "contact us" page if you "close for the weekend" so I don't think my email's in the void.
*Clear pictures. Also, I hate it when you can click on a picture thinking it will get bigger and all it does is open that same sized picture in a new window.
*Dimensions for your items. I bought something that I thought was far bigger than it was in actuality. My fault for not asking, of course. But I'd seen the same thing many other places about twice the size (and similarly priced).
~amey