It would appear you are already doing quite well,the book will give you the basics on navigation and the stuff you are carrying sounds about right.The truth is when I started walking around 28 years ago I hadn't got a clue what I was doing,lost count of the times I got lost and arrived at campsites at gone midnight,but it was a learning process and I looked at where I had gone wrong and made sure I didn't make the same mistake twice.One tip I would suggest is to look at plenty of photos of various mountain ranges,from the Alps to the Lakes etc and you will come to realise they all have the same basic features,passes,summits,ridges,tarns,,etc.Once you learn to identify the various mountain features navigation becomes far easier. Studying aerial photos of ranges is also a good idea.Before going on a walk I will study as many photos as possible so I can build a picture in my head of the various features,its quite easy to do with the amount of photos on the net,and if lost,I can start looking for familiar landmarks.One example is the Kissing Stones on Bleaklow,if you arrive there you will already have an idea of what they look like through seeing photos,they won't simply be lumps of rocks, but rather reference points you can look up on a map and find your postion.All walks have various reference points that are often marked on maps but you do need to have prior knowledge of what they look like if you want to make use of them.If they aren't marked on the map you can mark them yourself before going on the walk.You can always use GPS but in my opinion it takes the fun out of things and you have to remember most native tribes have a rather incredible sense of direction and its not been developed through using GPS!