Help with ordering parts?

I'm thinking about ordering a handful of parts from mouser, or digikey and I don't really know where to start. There sites are really complex and I'm not sure exactly what I'm looking for.

I have need for 8 pull down resistors, so I want to get an 8 -> 1 10k Ohm Resistor. I have no idea how to search for that.

Unrelated I also need a couple relays that I can switch on and off with my arduino (5v) that will switch 100w of 110v (a string of Xmas lights).

A handful of dual or tri-color LEDs would be fun too. Search for tri-color LEDs I get approximately 18 quadrillion hits. 99% of which I have no idea what they are. I just want a tri-color LED like one of these:

How does a newbie being to make sense of the massive catalogs that those guys have?

For those kind of parts (and the small quantity), are you sure you couldn't go with a surplus dealer?:

Those three are but a few that are out there; I could post a ton more. Most of these places also offer "grab bag" or "surprise boxes" which can (sometimes) be good for building up a parts inventory, especially of common parts like resistors, small transistors, and capacitors. If you are starting out, it would be a good idea to buy an assortment of various components, and outfit a multi-bin case with them to organize things.

Places like Mouser and Digikey are mainly good when you absolutely need brand new components, or when you need a certain IC that isn't easily found surplus or NOS (new-old stock), or when you need it new as well. Generally you can play and prototype OK with parts from surplus dealers, and grab the occasional IC or such from the large guys; when your prototype is complete, and you want to make it a permanent project, you can then buy the parts you need new, if necessary.

A similar operation in the UK....

Been around for years.

I also recommend searching ebay. You can get a whole raft of decent components for cheap.


I just placed an order from goldmine. Thanks for the heads up for those URLs. I haven't checked Ebay, is it pretty easy to find specific parts on there?

I haven’t checked Ebay, is it pretty easy to find specific parts on there?

Yeah. Obviously there is not everything on there but I recently purchased 5 LM35 temp sensors and 10 shift registers. Both were cheaper than I would have managed to get them anywhere else in a small order due to postage costs.

The search bar on ebay is a bit of a pain for looking up parts, if you don’t type it in quite right then things won’t come up. It’s pretty difficult to type something like LM35 wrong though!