Athdavrazar, zhey Sadie and welcome to the Dothraki forums!
From your question on the 'beginners' forum, it is clear, you have a good starting grasp of Dothraki. Probably the most challenging thing in Dothraki is the somewhat complex grammar, with things that are unpredictable, and somewhat unusual for an English speaker. Take time to carefully study the grammar information on the Dothraki wiki. Everything we know is explained there, and everyone that works on that wiki works closely with David peterson to ensure it is as accurate and up-to-date as possible.
The wiki also contains an online vocabulary. There is also the dictionary, which can be downloaded and printed out. It is also searchable. Despite any old dates on the forum posts concerning the wiki and the dictionary, both are fully up-to-date.
Check out David Peterson's blog at dothraki.com. This is where David makes official announcements of new things concerning the language.
Finally, consider joining us at 7 PM PAcific Time every Monday on the Dothraki IRC channel. This is where we get together to chat about Dothraki and a little bit of everything else. David Peterson often joins us, and this is your chance to ask him questions directly.
Although traffic on these forums is low, it is constantly watched by several of us. So, if you post a question here, someone will be by shortly to answer it.
Thanks for your interest in Dothraki!
Hrakkar