The Great Adventure is Robin Sutton's GWSH website. Robin has created and collected a range of scenarios for GWSH, both historical and fictional.
There are scenarios for players who are new to GWSH, as well as extremely challenging options for expert players. The After-Action Reports give a very good feel for GWSH.
There are lots of photographs too, as well as links to a whole range of resources. This includes Robin’s adaptation of Keith McNelly’s Scenario Generation System. An infinite variety of games are possible with this system.
Robin’s Wargamingnz Blog also features GWSH content.