For posting pictures, this thread has all the info you need:
How to post a photo in a thread
As to posting an ad, you first must be a Verified Provider:
Ladies, you may post a weekly ad in this section once you have been upgraded to Verified Provider.
Submit your info to the staff in your local area
1. website address (your website or advertising site)
2. referral from another provider or hobbyist
3. links to reviews from recognized members (any site)
Any combination of the above requirements which will sufficiently establish you as a legit provider will be accepted.
The verification process could take 24-48 hours.