First off, as a single father of two adorable little children, I applaud your effort.
Now, for the site design. If you do not have very much PHP experience, you could build the rest of your site in html and either link to the forum part from the main page, or even include it in an iframe as I did mine. As far as the forum software is concerned, it depends upon whether you wanna spend money on it or not. If you don't mind buying the forum software, you'll probably want to go with vBulletin, as it seems to have the best technical support and certainly a good set of features. If you prefer a free forum software, I highly recommend the YaBBSE , SMF version. I use it on my site, and it runs really well. It was really easy to set up and configure, has a lot of functionality built-in, and has been very stable ever since I installed it.
Another thing you may want to consider is a content management system, such as Macromedia's Contribute 3.1. It will allow you to build your site, maintain control of the look and feel of the site, and then give access to others to add content without them being able to do anything but that. It would make adding and updating the articles and blogs infinitely easier. Of course, there are lots of other content-management systems available. I just mentioned the Macromedia one because I know its capabilities, ease of use, and security are all right on the mark.
If you would like help with setting your site up, or anything else, please feel free to message me here or on ICQ (1097854), or if you prefer, you can email me. I'll gladly do whatever I can to help you bring a new resource for parents into fruition.
-Smitty