If they don't specify, then usually you're allowed to redistribute them. Usually you give them credit in your thread - say you trade for my Aggron, you then can redistrubute if you list the OT in your thread, for example, "Livewire's Aggron lvl 100" blah blah etc.
In order to make a thread, you need I believe 20 or so Pokemon with your OT/ID up for trade. IV bred shops need at least 10. Look at this thread here for information.
Organization is key, many seasoned and advanced traders use CSS and BB coding to enhance the looks of their shops. It will make the Pokemon pop right off the page. It can be pretty tricky and advanced though, even I can barely code correctly. Luckily the Trade Corner staff are pretty good at it. :]
Well I can be your mentor if you want! Haha. Pretty much everything you'll need to start trading in right there in the Trade Corner - read the rules first, etc, lurk around and study the threads you see there in the shops subforum.
Also, I can shpw you how to log on the Trade Corner's IRC channel, where you can talk & chat with other traders and the Trade Corner Staff.
And don't hesitate to keep in contact with me when you have more questions. My MSN is on my profile if you use it.