AD in small w2k network

I am building a small (25+/-) office network with one w2k server and w2k w9x nodes. It seems to me that a lot of the power of AD dissipates in such a small application. I am planning on one domain, and several OU’s (engineering, finance, management, blah, blah…) and outsourcing web hosting. Am I on the right track with this stuff? Advice is appreciated. Thanks.