Below is a list of resources for securing hobbyist electronics supplies. There are of course the general places you can go to find almost anything (Amazon, eBay, etc.), but these places specialize in those little known items that can take your project to the next level. I am always looking for more so drop me a line in the comment boxes when you come across new ones. I have left some off this list for brevity so keep your eyes out for others. Just as a disclaimer, I am not affiliated with any of these companies and these are just my opinions.
A great place to find new gadgets. Each year, they have what they call "free day" where customers can get up to $100 in electronics gear for free. Unfortunately, everyone knows this and so their servers crash nearly every time and it can take all day to get your order in. Regardless, this is one of my favorite sites for electronics stuff and they add new items to their supply each week. Check out their "Friday New Product Post" videos each week for a description. They also have tutorials and offer classes for noobs and advanced enthusiasts alike.
Started by Limor Fried (see the cover of March's Wired magazine), Adafruit sells everything from kits, to programmers, to test equipment, and darn near anything you could possibly need to start building your skills in hobby electronics. They are huge proponents of open-source and I think just about every project they sell comes with schematics and a bill of materials. They also have some of the better tutorials on the web for beginners, offer a forum for products, videos, and live chats on Saturdays.
I love this site. The company gets surplus electronics parts from all over the place and sells them to whomever they can for a fraction of the price. This site is awesome for building up your parts bins cheaply and finding strange items you didn't know existed. I think I have ordered from this site more than any other in the last year and I have yet to be disappointed. They usually offer some sort of deal each month (e.g. $10 off an order over $50), and I encourage people who may need some parts for quick prototyping to take advantage. With their prices and quantities, you would be surprised how far $50 can take you.
Not a site for electronics but rather plastic project enclosures. Once your project is finished you need to wrap it up in some sort of enclosure, assuming you care about aesthetics. It's actually really difficult to find a case other than a black plastic box. Polycase has a few different varieties so look them up next time you need to enclose your circuit for rugged use.
Sooner or later, any serious electronics hobbyist will want to start building up their own home labs. Multimeters, bench power supplies, oscilloscopes, function generators, and logic analyzers are just a few of pieces you may find yourself in need of. Luckily, Tequipment has got you covered with some of the lowest prices for new test equipment on the net. Based in New Jersey, I have yet to find a better place to buy test equipment. They have all the major brands, but unfortunately the site can be difficult to navigate if you don't already know what are looking for. I would suggest finding the product somewhere else and then buying it at Tequipment.
