Here are some sites with some kind of relation to the museum.

BETAMAX

The Beta Info Guide - a comprehensive American Betamax resource:
http://www.betainfoguide.com

The BetaPhile society - the (now defunct) American Betamax fan club:
http://condor.lpl.arizona.edu/~vance/betaphile.html

And some similar Beta pages in the UK:
http://www.colin99.co.uk/beta.html
http://www.palsite.com

V2000

A sub-page of the betamax fans' palsite:
http://www.palsite.com/v2000/index.html

Video Disk

CED Magic: a very active CED / Selectavision community, in the US:
http://www.cedmagic.com/index.html

DiscoVision - a collector's page for the early US precursor of the LaserVision format
http://www.oz.net/blam/DiscoVision/

PhonoVision - a remarkable site, by the man who "cracked the code" of Baird's TV records - TV signals on 78rpm records, from the 1920's and 30's. Includes animations showing the actual original recordings!
http://www.tvdawn.com

VHD DiscWorld: a US-based fansite for the VHD/AHD format:
http://disclord.tripod.com/vhddiscworld/index.html

The CartriVision Site
http://www.angelfire.com/alt/cartrivision

The Domesday Project - a LaserVision based 1980's update on the Domesday Book
http://www.atsf.co.uk/dottext/domesday.html

Other collectors and museums

LabGuy's World - a very rich site by a guy in California who claims to have spent over $30,000 on collecting old video machines...
http://www.labguysworld.com

A British collector of VCRs, TVs and other old technology -- fun diary section, too!
http://www.eclipse.co.uk/mikey/

An avid collector in Holland (in Dutch)
http://www.videoinfo.nl/

A very professional site for collectors of Broadcast TV technology:
http://www.broadcastcollecting.com/index.html

Quadruplex Park - a museum of broadcast VTR "dinosaurs":
http://www.lionlmb.org/quadpark.html

Passions Incongrues - a museum of VTRs and VCRs in french (with amusing english translations...):
http://sky.prohosting.com/vtrs/

Peter Schmitz collects various old tech, including V2000. (In German)
http://www.peterschmitz.com/Video_2000/video_2000.html

Hamid also collects various tech, including betamax
http://homepage.ntlworld.com/hamidk/betamax.htm

An excellent museum of early television
The Early Television Foundation and Museum

Miscellaneous

Video99 - If you need a tape transferred, Video99 offers the widest range of video cassette format transfers in the UK. Practically every format known to man!
http://www.video99.co.uk

The Farnsworth Chronicles - the startling story of who REALLY invented television.
http://farnovision.com

Some stuff on the VCordII format:
http://www.geocities.com/ResearchTriangle/ThinkTank/1935/index.html

A media history site, including sections on the dawn of film in Brighton, and early video:
http://www.terramedia.co.uk/index.html

An interesting sociology project, looking at video rental stores:
http://echo.gmu.edu/workshops/jgreenberg/

A review of the history of television, from an American perspective:
https://wyomingllcattorney.com/Blog/Business-Studies-Broadcasting-History