A work in progress.
Bentley Publishers (link below) publishes the best available tech info for VWs outside of genuine factory information.
Bentleys are (somewhat loosely) based on the genuine factory information, unfortunately, Bentley leaves out some information that they have decided for you that you don't want or need or shouldn't have.
Still, Bentley offers the best available to the majority of enthusiasts, so we buy and use. If you don't yet have your own copy, you ought to start budgeting for one soon.
The intent of this page is to offer links from various enthusiast sites that fill in some of what's missing from Bentley. Sometimes these sources offer info in plainer language than Bentley, some cover areas of the car not addressed by Bentley at all.

Technical articles, write ups, howtos and forum threads applicable to VW A1 chassis cars.
The organization below approximates that found in VW Factory shop information systems.
Exceptions are made where a topic could, by some logic, apply in more than one section, such as  Dynamic Oil Pressure Warning Systems. VW includes DOPWS info only in the lubrication section, here, DOPWS info can be found in both the Lube and Instrumentation sections.
All links will open new windows.

Bentley VW manuals, paper, CDRom, web.
Buy direct from Bentley Publishers or use the ISBN information to aid your on-line shopping, or order it from any retail bookseller.

Group 0, General
How to Ask for Help in Automotive Forums
Cabriolet Specs
General Maintenance.
General Lubrication Info
How to google Search
About "Triple Square" "XZN" bolts.
A VIN Decoder.
Totally NOT A1 Related, Volkswagen Vanagons with Subaru WRX Turbo engines
Some Suby>Vanagon Conversion parts.
Kennedy Engineering, the old standard in adapter parts for whatever engine to Air Cooled VW Transaxles.

Group 1, Engine
1, General.
10, Crank and Block
15, Head, Cam, Valves
17, Lube System
19, Cooling System

Group 2, Engine Management
20,  Fuel Storage and Supply
21, Turbo

23, Diesel Injection
24, EFI
25, CIS
26, Exhaust
Exhaust spring clamp tools,
Homebrew. (sorry, I have no proper credit for this pic)
Professional. dead link
27,  Starting and Charging
28, Ignition

Group 3, Transmission and Clutch
3,'s ratio page
Broke's pages.
funksoulkitty's 020 trans build, 02J teardown, 02J build.
Speedo drive gear details.
020 trans fluid change
cheapassron's Homebrew 020 Transaxle Tooling. dang, dead link, was good stuff here too.
rabbitnothopper on the 'tex found some of cheapassron's stuff at the internet, I copied the photos I found there, they are now in this directory.
Broke's Reverse Light Switch Autopsy
30, Clutch
32, Torque Converter
34, Manual Trans Controls and Assembly.
35, Manual Trans Gears and Shafts.
37, Automatic Trans Controls and Assembly.
38, Automatic Trans, Case, Gears and Shafts.
39, Differential

Group 4, Suspension, Brakes and Steering.
40, Front Suspension and Drive Axles
42, Rear Suspension.
44, Wheels, Tires, Alignment.
45, ABS Brakes
46, Brakes, Mechanical.
47, Brakes, Hydraulic.
48, Steering.

Group 5, Body Assembly.

50, Body, General
Dimensions, 1, 2, 3, 4 and 5
Pickup Dimensions, 1 and 2
The definitive A1 paint code guide.
Car on a Wooden Rotisserie restorations, 1, 2.
A1 Crash Testing.
Trammel Points.
ericb49's Braced Cabriolet.
Rope Installed Glass.
55, Hoods and Lids.
57, Front Doors.
58, Rear Doors

Group 6, Body Externals.
60, Sunroof
61, Convertible Top
63, Bumpers.

66, Accessories, Exterior.
69, Seatbelts, Air Bags.

Group 7, Interior
7, General Interior
70, Trim
72, Seats

Group 8, HVAC
80, Heating and Ventilation.
87, Air Conditioning.

Group 9, Electrical.
90, Instruments.
91, Radio
Aktiv, 1 and 2
92, Wipers and Washers.
94, Exterior Lights.
96, Interior Lights and Accessories.
97, Schematics, Wiring.

Credits, oh yes, credits are due!!
Many sources were used compiling this links page including

A Huge Thanks to all these sites for your positive contribution to the worldwide auto enthusiast community.

2009, tolusina on the 'tex and ;)