The Microsoft Enterprise Content Management (ECM) Team Blog has a wealth of information regarding Microsoft Office SharePoint 2007.
One interesting thread is a three part seriies on Building a Real World Extranet Application with MOSS 2007, of which the first two parts have been posted. It is written by real work SharePoint MPV Shane Perran and lead architect Jared Rypkema.
Part 1 sets the stage in how to organize the site and defining the content types. The comments to the posting point to other articles that provide additional information as well.
Part 2 describes site and content customization (site branding), howto create custom pages, and how to separate the presentation.
Performance is always a concern when doing a SharePoint site. A recent posting describes how to increase performance for MOSS application using the PortalSiteMapProvider.
Often, those ISV's who are considering MOSS are looking to see what other sites use it as a development plaftform. The posting on WSS Demo provides fifty or so sites.
Michael Gannotti On SharePoint is a great blog that among other things provides a set of six videos that show how to create a knowledge center. The videos show how to create a formalized process to ensure that authorative documents are locked down and logged for auditing.
The Community Kit for SharePoint team has made tremendous progress over the past couple of months. The team has already published a user group edition, and a Community Kit. They are on the verge of releasing a few components and editions, as shown in the CKS 2.0 Announcement.