I'm not driving self esteem - I'm just well equipped to say that you can't start without knowing the basics. I actually spent nearly 8 years as an engineering mentor, teaching others so I spread my knowledge. I also sit and help people but to be honest sometimes it's hopeless as they just don't have the fundamentals and aren't interested.

My problem is that the fundamentals are completely wiped out by the whole Maker movement in favour of short-cutting and getting things done, regardless of how dangerous or stupid they are.

With all the free resources out there, it's probably best to do the following. This is my personal recommendation and it's what I throw people towards who want a solid understanding of the subject:

1. Start with Khan Academy and do at least up to the end of Linear Algebra. Make sure you cover trig as well. Do the first few sections on arithmetic with a calculator or skip them if you can't be bothered. Arithmetic isn't all that important in maths. Grab a reasonably new Casio calc with solver and calculus functions such as FX-991ES as well.

2. Pick up the NEETS guides from [1] and work through the first module [2] until you get a rough understanding of what electricity is. Some eye openers in there which surprise a lot of people.

3. Grab a copy of "the art of electronics" and the associated student guide and work through the latter using the former as a reference ONLY (seriously the latter is an awesome book which contains some real practical hints and tips that are missing from everything else). The main art of electronics is a disjoint mess of information but the student guide uses the right approach.

4. Move slowly to AC circuits, referring back to Khan Academy if you get stuck on the maths and NEETS as the fundamental information.

5. Rinse and repeat. You will be able to chose your own path when you get through those bits.

Also, best advice in the world - buy an analogue oscilloscope - an old 25MHz one can be had on ebay for virtually nothing. It doesn't have to be a nice one - just something that works. I've got one that is 35 years old that is fine - it cost me $20! Ignore those digital ones - they're a piece of shit unless you want to spend upwards of $500.

You can probably do the whole series in a year or so with $100-200 investment which is less than an iPhone.

If you get royally stuck, visit http://forum.allaboutcircuits.com/ and there are plenty of us who will help you out.

[1] http://www.phy.davidson.edu/instrumentation/NEETS.htm

[2] When I say work through the modules, I mean buy some components and actually build some stuff and play with it rather than just mindlessly sap up the theory.