Sci.Electronics.Repair FAQ has some excellent material on repairing electronic equipment.
ePanorama is an enourmous source of information on all aspects of electronics.
New Wave Concepts link page is very useful.
There are some excellent notes on using infra-red from the Zetex website. Zetex are a transistor and IC manufacturer based in Oldham near Manchester.
If you want to understand infra-red remote control there are two laboratory exercises: lab 4 and lab 5 at the Department of Electrical Engineering, Northeastern University in the USA on designing and building an infrared remote control.
Rentron electronics have some good circuits for infrared remote control. There is a simple design for a remote control transmitter and receiver at Reynolds electronics site. However, their Fire-Stick II remote control looks to have a particularly good design using common and straightforward components.
Dave Negro's notes on infra-red remotes has some useful infromation and links.
David Tait is a lecturer at Manchester University. He has a good set of links and programs for PIC microcontrollers.
Circuit Exchange International has some useful circuit designs.
Pinouts of various connectors
An excellent website on connecting PCs to electronic circuits is produced by Jan Axelson of Lakeview Research
There is usually a lot of data on manufacturers web sites. Look for data sheets and application notes. Application notes usually provide circuit diagrams which can be adapted to your needs. Manufacturers web pages oftenrefer to OEMs, this stands for Original Equipment Manufacturers, you are an OEM if you are trying to design a new product so look for OEM data.
RCWS lists links to semiconductor manufacturers.
Plano also has a list of semiconductor manufacturers.
Paul Reynolds pages have links to manufacturers as well.
Manufacturers data sheets are linked from this page.
Arizona Microchip produces thePIC microcontroller.
Atmel specialises in flash memoryproducts and make the AVR microcontroller.
Holtek produces some specialistICs, e.g. chips for DTMF dialling for telephones.
ISD specialise in chips for recordingand playing back sound and speech processing chips.
Scenix makes the fastest 8 bitmicrocontrollers available at the moment.
Zetex manufactures transistors anddiodes so has good information on using discrete components.
mainly produce programmablelogic devices
AMD (Advanced Micro Devices) producehigh performance digital ICs and communication ICs
AMP make a wide range of products, mainly for special applications
Analog Devices produce a wide rangeof analog chips.
Burr-Brown produce analogueICs.
Intel manufacturer of microprocessorsand microcontrollers.
Motorola produces a wide rangeof electronics components and products.
Siemens are a large semiconductormanufacturer with a wide range of products.
Linear technology not suprisinglyis mostly involved in linear IC production, but has a wide range of products.
Texas Instruments produces a wide rangeof electronics components plus calculators and other consumer products.
Farnell are one of the larger suppliers of electronics components and have data sheets available online. You will need to register to use the site.
RS (Radio Spares) is another of the large suppliers with manufacturers data sheets and their own datasheets online. Again, you need to register to use the site.
Maplin Electronics is a supplier aimed at amateurs. Maplin has shops all over the UK as well as selling by mail order and usefully has a shop near the college on the High Holborn (click here for map and opening times).
CPC is used by most repair shops for supplies. They have a wide range of general electronic components at good prices as well as spares televisions, videos and other domestic electronic equipment.
Rapid Electronics is good supplier with a more limited range than RS and Farnell but much lower prices. They have not been available on the web before and are only just establishing their site.
JPR Electronics are another smaller supplier with good prices but a limited range.
Dial Electronics supply difficult to find and unusual components.