I've split these links into four sections; the first section is for MAG groups in the Thames Valley area and beyond, then there's a section devoted to other local bike clubs followed by a list of all of the current Major Bike Importers in the U.K. Finally, you'll find some other interesting general biking sites that I've found and have found useful or entertaining.

MAG groups in the Thames Valley area and beyond:
F.E.M.A: http://www.fema.kaalium.com/
MAG UK: http://mag-uk.org
MAG Sport: http://www.magsport.com
MAG Cumbria:
Oxford MAG (Reformed Group! New site!): http://oxford.mag-uk.org
Reading MAG: http://www.LionRally.com
Rushden MAG: http://www.radmag.20m.com/
South Herts. MAG: http://www.btinternet.com/~miyamoto/mag.htm
South Oxon. MAG: http://www.freeyellow.com/members4/sox-mag/index
S.H.A.G. MAG: http://www.geocities.com/MotorCity/7704/index
Thames Valley MAG: http://thames-valley-region.mag-uk.org
West Oxon MAG: http://www.westoxonmag.org.uk
Windsor MAG: http://www.wadmag.org.uk

Other bike clubs in the area:
AJS and Matchless Owners Club: http://www.amoc-eastberks.co.uk
Bucks British and Classic Motorcycle Club: http://www.bbcmcc.freeuk.com
Barrel Bikers MCC: http://www.barrelbikers.co.uk
Insane MCC: http://www.insanemcc.com
Uninvited RRC: www.uninvited.co.uk

Bike Manufacturers: (Most info. from M&P)
Aprilia http://www.aprilia.com
BMW http://www.bmw-motorrad.co.uk
Buell http://www.buell.co.uk/
CCM http://www.ccm-motorcycles.com/
Derbi http://www.derbi.com
Drysdale http://home.mira.net/~iwd/
Ducati http://www.ducati.com
Gilera http://www.gilera.com
Harley Davidson http://www.harley-davidson.co.uk
Honda http://www.honda-motorcycle.co.uk/
Italjet http://www.italjet.com
Jawa http://www.jawa.cz
Kawasaki http://www.kawasaki.com
Moto Guzzi http://www.motoguzzi.it/eng/
MuZ http://www.muz.de
Piaggio http://www.piaggio.com
Suzuki UK http://www.suzuki.co.uk
Triumph http://www.triumph.co.uk
Yamaha http://www.yamaha-motor-europe.com

General biking sites:
Bikersweb.co.uk Cyberzine: http://www.bikersweb.co.uk
Bikesafe 2000: : http://www.bikesafe.co.uk
Chiltern Motorcycles, supplier of Lighting upgrades, general spare parts and motorcycle accessories including classic bike oil filter kits: http://www.norbsa02.freeuk.com
Panther Publishing, Publishes varipus motorcycle books Phanther Publishing
Dragons 666: http://www.dragons666.freeserve.co.uk
Dream Machine Paintwork: http://www.dream-machine.co.uk
"Englands's Rose": http://www.fsvo.com/englandsrose/door
GDL Motorcycle Parts:
FEMA's Simon Milward's Round the World Millenium Trip: http://www.millennium-ride.com/
Lets-ride.com: http://www.lets-ride.com
www.mermoto.co.uk: Thinking about a new bike? Then check this out and get the deal you want!
Moto Directory Links: MotoDirectory.com - loads more biking links!
Motosites.com: http://www.motosites.com
Motorcyclespares.net: http://www.motorcyclespares.net
Motorcycle-UK's all round site: http://www.motorcycle-uk.com
M&P: http://www.MandP.com
Oxfordshire Biker Cafe: http://www.obc.ukwebz.com
Precision Motorcycle Paintwork (Bedfordshire):
Ruby Moon, Wycombe Ruby Moon - Putting the 'Hi' In High Wycombe!!
Sapphire Moon, Thame Sapphire Moon is the New Age, up market, counterpart of Ruby Moon
The Trail Riders Fellowship: http://www.trf.org.uk/
Tyresales UK ( On-line shop for all your motorcycle tyre needs): http://www.tyresalesuk.co.uk
UltraSeal (Dead useful puncture seal product): http://www.ultraseal.biz
Thames Vallet Police Safer Rider Site
www.thamesvalley.police.uk/safer-rider

Please let me know if you find any dead or inappropriate links. Thanks!