- I have divided my favourite early music links into different categories:

research

RISM online database series A/II: Handschriften 1600-1800
RISM Library Directory listing adresses of all libraries worldwide
New Grove of Music and Musicians online
Deutsches Musikgeschichtliches Archiv Kassel (includes music from several smaller libraries in Germany)
Nederlands Muziek Institut (former Gemeente Museum
Den Haag)
The Hasse Project
British Library Music Collection (London)
Doctoral Dissertations in Musicology online archive
Bach Digital with online manuscripts by J.S. Bach
Baroque Bowed Bass Instruments lists the different types, tuning and countrys of appearance
Musical instrument museums all over the world

early music groups and orchestras

Academy of Ancient Music UK
Al Ayre Espanol, Spain
Concerto Copenhagen - Danish Baroque Orchestra, Denmark
Concerto Köln, Germany
Freiburger Baroque Orchestra , Germany
Les Musiciens du Louvre - Grenoble, France
L'Orfeo Barockorchester
Nederlandse Bachvereniging, Netherlands
The King's Singers, UK
Opus X, Finland
The Orchestra of the Sixth Floor, Finland
Portland Baroque Orchestra, USA
Sonatori de la Gioiosa Marca, Italy
Tafelmusic, Canada
Edding Quartet, a classical string quartet on period instruments, Belgium/France

string instrument and bow makers

conversion table PM (Pirastro) to mm
Article on making gut strings by Daniel Larsen
Nils Wieboldt's String Calculator (!)
Aquila Strings
Gamut Strings
NRI
Damian Dlugolecki
Pirastro

iconography

Nuremberg chronicle
violin iconography (!)
recorder iconography

early music festivals

music festivals worldwidea list sorted by countries
Holland Festival Early Music Utrecht

early music institutes

Koninklijk conservatorium Den Haag (NL)
Sweelinck Conservatorioum Amsterdam (NL)
Royal Academy of Music London (UK)
Royal College of Music London (UK)
Schola Cantorum Basel (CH)
Musikhochschule Trossingen (D)
Hochschule für Musik Bremen (D)
Conservatoire national superieur de musique et de danse de Paris (F)
Koninklijk Conservatorium Brussels (B)

online early music magazines

Concerto (D)

other stuff

"on a bike through France" My roadbike cycling log (with GPS)