I can give you a couple of good book recommendations. Probably the most used Electronics book I have is:
"Electronic Systems" by M.W. Brimicombe ISBN: 0-17-448067-9
I used this book frequently back when I was just beginning in Electronics and I still refer to it as a reference. It covers quite a wide range of the electronics field and does start at the basics so it's a good introduction. The only negative point I'd put to it is that some of the topics covered are a bit mathematical, more so than perhaps they need to be and sometimes that can make the concepts more confusing. But definately a good book and it does have examples / problems with answers at the back.
Another book I've found extremely useful is:
"Discovering Electronics" by Roy Edwards ISBN: 1-85805-088-X
This book also starts right at the basics and educates you right up to BTEC Diploma Standard, but it takes more of a practical approach backed up by theory so in that respect it's very useful. This book also has problems for you to do at the end of each topic. The downside is that since it's very practical based (which really is a good thing), you do need to have some basic equipment in order to follow all of the examples, problems and experiments.
If you want to go even further you can also try this book:
"Electronics 4" by D C Green ISBN: 0-582-24517-6
This book aims to educate you to HND level and it's very good, but it's probably aimed more at someone who already has an understanding of the basics so it might be one for you to consider at a later date. I only own version 4 of this book but you might want to take a look at versions 1,2 or 3 as they increase in difficulty with 1 being the absolute basics and 4 being HND level Electronics. Again the one critisism I'd give this book is that at times it's very mathematical, but then this is a HND level book so you'd have to expect a certain amount of boring maths!
Hope this is useful
Brian Hoskins