1-Promo Code for Biz? 2-Understanding Free Online dB for Biz

1-Promo Code for Biz? 2-Understanding Free Online dB for Biz

We want to put a form and dB on our web site so users can either...
- post or
- look things up

1 - Where do we find a Zoho Promo Code for free "Embedding" ??
2 - Can we do the free online/public dB with out the ZoHo logo or advertising?
3 - Can we put up to 5 Public dB's on a business site for free?
4 - Cost to get more storage only or must you pay $300/yr & upgrade?

Thanks for any help.