I too started with that. A magnificent machine. Simple, with no chips to poke around and configure, so the only way to do anything was to write clever code.
I didn't realise how important the manual was until The Register quoted Steve Vickers, the author of the manual:
When I was writing the manual, the one thing I really wanted to avoid was the kind of brick wall that you can get to when you're just following along and then suddenly hit a wall where, unless you take on board a huge amount of understanding, you just can't make any progress.
I started reading that manual on the day I brought the Spectrum home, and I was programming by the next day. And though I can't say how he did it, he also succeeded at teaching me creativity in programming:
One of the hardest things to teach in programming is that it [programming] is a creative activity. It's not just about knowing the rules for the programming language and how to avoid compiler errors, it's about how to have enough control of the machine so that you can get it to do creative things.
An uncle visited about a month later, looked at what I was doing and asked why. I remember realising that the question was from across a chasm and that I had no real way to answer. I was getting the machine to do creative things and had no idea how to explain anything about it. How was I taught that? Amazing technical writing.