New webmaster - a few SEO questions

Hi everyone,

I was referred here by a friend and spent the last week reading up on threads and found this to be an absolutely invaluable resource - pity I didn't find this 6 months ago when I started!

To give a brief background about myself, I work full time and have been working on a gaming affiliate site as a side-project with a partner and we are both very happy with it so far. I have been learning SEO from scratch and am learning new things everyday, but I was hoping there were a few things that someone here could maybe clarify for me, because I am a little confused.

I started with the site as a .net domain, and bought the .com domain about 6 weeks ago for $100 (domain age from 1998). The .com domain came with a few backlinks, but my offpage SEO is sorely lacking. I recently bought a program that will help spin articles to be submitted, but I am a little hesitant about at what pace I should be submitting articles, as I don't want google to suddenly see that I have 1000 new backlinks and get penalized. How many articles should I be submitting per day? 10? 100? 1000? I'm totally clueless here and could use some advice to avoid being red-flagged.

I also have about 50 pages of content, but google only has about 25 pages indexed - it seems to have indexed some of my newer pages but skipped over the older ones. Is this normal? I have a sitemap and an xml sitemap and my site is pretty well interlinked - what can I do to get them to index the rest of my pages? My site is updated several times a week.

Thanks for reading - I appreciate any feedback to help me advance my SEO knowledge