Claire George has recently set up a blog for the seventeenth century community. She hopes to create a sort of virtual 'coffee house' for those of us interested in the period.
British History Online from the Institute of Historical Research contains digitised versions of a growing number of important sources for early modern British historians - often those bulky multi-volume projects that are hidden away in university libraries (eg, Calendar of State Papers Domestic; Victoria County Histories; House of Lords and House of Commons Journals); and much more, including maps of London. It has both browse and search facilities. This is going to be an extremely useful research resource!
Teachers looking for ways of making effective use of the web for teaching may be interested in a new H-Net discussion network, H-OEH for Online Education in the Humanities.