Using Windows Home Server as a platform for server applications such as accounting software (e.g. QuickBooks) is unsupported. A number of peopple have done so, but you may find that you're on your own as far as solving problems is concerned.
You'll find a lot of good information on the Windows Home Server
microsite. In particular, the documents available through the
Help page will explain a lot about the product.
I'm not on the WHS team, I just post a lot. :)