As a guy interested in science and engineering, I like to make stuff. My desk and room is littered with electronic oddities and various materials and tools. Very few things can replace the feeling one gets when something that you have invested countless hours into ACTUALLY WORKS!
However, very few things can replace a good set of plans when you are working on a project. Sure you could peruse the internet until your eyes bleed in your search for good information, or you could scour the local library for a book that wasn't made for the layman. But, if you really want specific, relevant design data for a project, I suggest getting a good set of plans every time. (Unless you are making something entirely novel, in which case I wish you luck! ;)
The great thing about plans is that you don't have to follow them to the letter. Personally, I like to get a set of plans, examine them alongside other information I have gathered, and then make tweaks and adjustments as I see fit. That way I come up with something truly of my own creation that is pretty decent.
So, if you are interested, here are some good sites that offer pretty good plans for various nerdy projects:
1. Information Unlimited - These guys are pretty awesome. They have plans for most everything, and they offer to supply you with a lot of the materials you need. So, if you need anything from tesla coils to lasers to pest control gadgets, they are the people to see!
2. Carl's Electronics - A rather splendid website that has a wide array of electronic plans. Ranging from radios to gag toys to personal security projects, Carl pretty much has it all.
3. Emission Technologies - This is only one set of plans, but it is to make a CO2 Laser! I haven't broken down and bought the plans myself, but from the site I am awfully tempted.
