Google probably displays your home page because it thinks it is a relevant answer to the search the user did...
One way that would help making your "post" pages more important is to display the full-content of the post on the home page for only the last post ; and, for the next ones, only display some excerpt, or a summary, or something like that.
It would make your post pages more important... But that would also mean having a "less important" home page... Which may or may not be good.
Google also uses links from other websites : if many important sites link to your homepage, and only a few link to your post pages, google will think the home page is more important than those.
As your blog is about PHP, one nice thing could be to be syndicated on http://www.planet-php.net/ : it allows many people to see your blog entries -- and is nice for visibility too (both to users and to google, as it has a high pagerank, I suppose)
Still, google is probably already exploring your whole site : if there are links to your post pages (there are on the home page, at least), google will visit thoses one day or another...
One thing I just noticed, though : your first post was in june, and you've been active only for a something like a month and a half ; it is not that long, especially if not many websites have links to yours...
In the end, there is only one secret : the more you'll write interesting stuff, the more people will find your blog interesting, the more they'll talk about it and include links to it, the more google will see about it too, the higher you'll be in results, and so on ;-)
But, yes, it takes time... Especially if you want to only write interesting posts -- and you should not post crap just to have lots of content !
I just saw you have a first blog on http://code.seanhess.net/ and that you now have another one on http://seanhess.net/ ; do you think it would be wise (depends on your content, on what you want and all that !) to move all blog-posts from the first one to the new one, adding permanent redirections on the old pages to the new ones ?
You might also want to take a look at some articles on the net, as well as some questions/answers here on SO, that could give you some useful advices. For instance :
And if you search with... google for instance... you might find many interested articles on the net about that too...