You asked, so I'm going to give you my opinion straight up. I hope I don't offend anyone here.
The site is super active and contains some good information. Everything is laid out in very clear cut ways that could absolutely help someone learning about DD. It covers a vary wide range of topics that related to DD issues and they sell inexpensive manuals, some of which have been great.
My complaints would be that it is definitely based in traditional roles, and most posts seem to suggest that the writers are the first ever to discover that DD requires communication, respect, and has challenges that relate to everyday living ;-). If you can look beyond the insensitivity of the Hoh who writes most of it, it can be a very good source of information. Anything written by his wife typically doesn't contain anyone of that, and she is intelligent and well-rounded (they don't state directly who writes it, but it's obvious). It can be fairly judgemental compared to this site ( i.e " some of your may be aware of the Spencer Discipline plan, but we don't reccommend it unless you hate your spouse and want to fight all the time"). It also regualrly, if apologetically, suggests that women are typically child like creatures prone to acting out in public, defiantly selfish in their spending on clothes and jewelery when bills need to be paid, very likely to cry and quiver in fear at the first suggestion of punishment, etc.
All that being said... I literally mean that if you can look past the stereotypes that are clearly ingrainged within the authors understanding of DD, the no nonsense blogs and issues that are discussed are very much the same issues that all of us face when in a DD situation. They are discussed in an open fashion and, perhaps because of no need to feel "PC", are very frank and direct. Once I ignored the associated gender roles and arrogance, I found many articles to be valuable. I have also noticed a bit of an evolution in the posts...the earlier posts seem far more judgemental than the newer ones, so I have to give it credit for that. Deifnitely worth a visit, but be prepared for VERY traditionalist views.