Unfortunately, submission to the search engines really won't do anything for you at all.
Our own Jennifer Laycock has written a book, small Business Guide to Search Engine Marketing
that you might find helpful. It's not free, but it's definitely worth the price of admission (and then some).
If you'd like to start with a free resource, you might want to take a look at the Tips for New SEOs thread at the HighRankings.com forum
. It's a collection of articles that will help you learn more about the things that really do matter for search engine optimization. (Full disclosure: I'm a moderator at HR, so I may be a bit biased, but I think that thread's a pretty good resource.
To answer your final question, your message and my reply are each "posts." Together (with any other subsequent posts that may be added as part of this same discussion), they will form a "thread." If you think of it in terms of the "offline" world, a thread
corresponds to a conversation. As each participant in the conversation makes a new remark or observation, that would correspond to a post
Hope this helps!