This list will contain sites, divided up into several categories that the average electronics hobbyist would find useful. I would appreciate suggestions on sites people have used that they found useful. This list will not include stores of components suppliers - these are contained within another resource, see here. This list will also not include software - these can be found in another resource, see here. I have tried many electronics sites, especially forums and personally I would say this one of the most active and certainly gives the highest quality and widest range of advice. All the sites in this list will be free for use.
Information Sites, Schematic sharing and Forums Electronicspoint http://www.electronicspoint.com/ Well, you have got to love this one otherwise you would not be reading this! Schematics.com http://schematics.com/ A site for sharing schematics of all types, only has a few features though and is not very active. However the lack of features does make it extremely easy to use. Sparkfun https://www.sparkfun.com/ This site mainly sells electronics items however it has an active forum, tutorials and resources. Adafruit http://www.adafruit.com/ This site, like Sparkfun, mainly sells electronics items however it has an active forum, tutorials and resources such as sketches. DesignSpark http://www.rs-online.com/designspark/electronics/eng/ This site has many features including software downloads and a design sharing feature. The design sharing feature enables improved collaboration compared with Schematics.com, having both comments and design stages. Hackaday http://hackaday.com/ Site based around re-making stuff, features such as shop, ideas and a moderately active forum. An active "projects" area conatining many great circuit/build Arduino http://arduino.cc/ The official site for all things Arduino Raspberry Pi http://www.raspberrypi.org/ The official site for all things Raspberry Pi TIDesigns http://www.ti.com/general/docs/refdesignsearch.tsp chopnhack: "has ready made solutions that you can pick apart and change, but they are tested and have gerber files. Of course they only use TI parts, but so what?! Nice of them to share completely tested solutions." Talkingelectronics http://www.talkingelectronics.com/te_interactive_index.html This site contains useful information on schematics and was created by an electronicspoint member Williamson Labs http://williamson-labs.com/ A large variety of tutorials. Warning: if you allergic to GIFs it is advised you do not visit this site. Roboroom http://www.robotroom.com/index.html An excellent site for robot information
Tutorials Arduino Digital_Read tutorial http://arduino.cc/en/Tutorial/DigitalReadSerial Explains how to set up a simple push switch circuit, have the Arduino sense it and display the data on the connected desktop
The Ben Heck show https://www.youtube.com/user/thebenheckshow/videos?flow=grid&view=0&sort=da The Ben Heck show is brilliant, Ben Heck takes user requests and builds them. Watch it now.
IoT and IoT platforms Xively https://xively.com/ An IoT platform. Unfortunately there is currently a waiting list for a free developer account, this site also appears to be entirely or almost entirely corporate based. From previews the features appear extremely easy to use (notes will be improved once a developer account is obtained) Allseenalliance https://allseenalliance.org/ This is a completely open source project organised by Linux. Does not appear to be as clear to use as Xively however still under development Plotly https://plot.ly/ Can use devices such as Raspberry pi or Arduino to upload graph data. Lots of developement currently happening. This site is not totally corporate based as it the site advertises "free for unlimited public use no matter what" (see here: https://plot.ly/online-graphing-and-statistics-for-educators/)
Projects, events and Misc. FabLabs https://www.fablabs.io/ A physical project in heavy development. FabLabs stand for Fabrication Laboratories, centred around advanced manufacturing, the FabLab movement has and still is going around the world. There may be a FabLab near you or there soon may be! Currently communication between people on this is not clear but one of the planned features is a forum (as you can see at the bottom of the linked page). Hackspaces http://www.hackspace.org.uk/wiki/Main_Page UK only, however there may be a equivalent for other countries. Excellent gathering spaces for intellectuals, a wide variety of knowledge is found in these places, in anything from computer based art to old analogue designs. Even if there is not one currently in your area (however, this is extremely unlikely as there are so many all over Britain) do not despair, one month there was no sign of one in my area, the next one with over twenty members sprang up with a rented space.
Robotics BEAM robotics wiki http://www.beam-wiki.org/wiki/Main_Page Supercap2f reports this is an excellent site
Letsmakerobots http://letsmakerobots.com/ A very active forum style site (the actual forum section is not very active however) with useful information surrounding robots and projects useful for robotics. Many uploads of robot projects. Custom part calculator http://www.custompartnet.com/quick-tool/weight-calculator This may just be THE most useful site when designing parts for print on a 3D printer. The given link directs to the section containing weight, which is the section I personally use most.