Rick,
First of all I want to say that I think what you're doing is great and Noah is adorable. I am a mother of twin boys that are 5 months old and have a good friend with a 3 year old that has down syndrome.
As far as choosing words to rank for - It looks like you have a good list, have you taken a look at Google's adword keyword tool? This can give you an idea of the competitiveness of these keywords. Also, look at the keyword difficulty tool on SEOmoz.
Once you decide that you know which keywords you want (it already looks like you have) I would recommend using those in your page title tags on pages that it makes sense for. - I haven't looked, maybe you already did this.
For your homepage, I would be careful in making changes to the page title and description as it can hurt you if you are already doing well with the ones you have. I do recommend deleting your meta keywords as these aren't used anymore and there is discussion that they may even hurt you.
As far as ranking for the wrong spellings, I see where you're coming from and have tried to do it in the past. Now, I would recommend not doing it for a number of reasons. First of all, you don't want to decrease your site's trustworhiness with incorrect spellings. Also, because Google often does the "did you mean __" thing or showing results for the right spelling, I would stay away from trying to rank for the incorrect one. Google may also dock you for it.
As far as your category ideas, I think it's a great idea to put them into categories. Can you put them into categories and keep them in a timeline list too? If you can, you'll also want to make sure that the links in your category lists aren't different, or Google may see this as duplicate content. See - http://www.seomoz.org/blog/duplicate-content-in-a-post-panda-world
Besides these things, I would recommend keep posting great content as you are, building links, keep reading SEOmoz, and watch the prowebinars if you have access. Rand did one on link building earlier this year that I recommend. Also, work on social marketing (I'm not sure how much you've done already)
Good luck! I'll wait for your response
Holly
