Eriks Flygsidor (Erik's flight pages) An extensive site only in swedish about the swedish jet fighters.
Svenskt Militärhistoriskt Bibliotek (Swedish Military History Library) Only in swedish but contains information about aeroplanes in the swedish air force.
Svensk Flyghistorik Förening (Swedish Aviation Historical Society) Good multi-language site about swedish aviation history. It also have a good forum.
IPMS Stockholm (IMPS Stockholm) Mostly for modelers. Good forum, building tips and references.
Svenska Flygvapnet (Swedish Air Force) The official site of the Swedish Air Force. Has links to the existing wings.