My students

Sorry for not writing, this week was the first one with the new teaching hours and the job takes more time that I expected.
I still spend loads of time preparing my classes. I'm using a couple of books from Cambridge's English as a foreign languages (see picture) and they're very good and they do made my teaching life easier, but still have to go through each lesson to make sure that I understand what's there and that I could answer any grammar or vocabulary question. I know that I don't need to know everything, but I must know the basic grammar for the lesson, at least.
As I was learning English for ages and my first language is Spanish as it's the case for most of my students, I'm sort of know where the problems are likely to arise and which words are going to cause problems, but I still need to refresh my grammar.
So, most of my classes are done with and by the book, but there's a couple of groups that are harder and more time consuming. One is a group of 3 computer geeks, they're a joy to teach as they're language skills are really high and it's a challenge for me to find material for them. Plus they have a wicked sense of humour and the classes are nearly always fun. I use a wide range of different magazines from Vanity Fair to The new scientist or Wired, videos that I find in you-tube, news that I got from the BBC, etc etc. They take turns to read aloud and we discuss new vocabulary, pronunciation, grammar (sometime), idioms and, of course, opinions. For the next class I'll try to find some interview or lecture in a podcast with a transcript, then I'm going to erase some words, phrases, idioms, etc in the page and they're job will be to fill the gaps.
The other challenging class for me, the one that I finish with a screaming headache is with just one student, an absolute beginner. We have 2 two hours lessons a week and my goddess... it's exhausting! I've no book for him and it's hard to think where to start with a totally new and unknown language. I'm seriously considering buying a book for him, even though I have to pay for it myself, I may need to use it in the future with another student. But I cannot find an EFL book for absolute beginners that's not for children!! Please let me know if you know one.
This guy is a new employee in a factory, he's a 43 years-old engineer in charge of all the machines and a team of 7. The company is a multinational with branches and factories all over Europe, even one in Scarborough, where he visit last week and where he learn his first 2 words in English: ok and beer. He's got the job with the understanding that he's going to learn English so he can travel and be able to communicate, exchange information and so on with other people all over Europe and the company is paying me to take him there. He never really needed or even wanted to learn English, he doesn't go to see movies in English with subtitles, only dubbed to Spanish or Catalan, he never liked or even listened to music in English and had no desire whatsoever to learn a new language, he's been told he has to take lessons and that the one and only reason he's doing it.
During our first class, when I was assessing him and where we were, his phone rung half way into the lesson and he answered and started to giggle like a teenager. He then told me that it was a ruse, as he wasn't sure that he was going to like me or the classes, he arranged for one of his guys to call him at that time and provide him with an excuse to leave the class if it was really boring!!
To my credit, he decided to stay and endure the class and I took this a compliment and we had a laugh. I'm still teasing him about it!
However, this is going to be tough and I really don't know how I'm going to do it.

Any ideas for teaching plans, suggestion for what the basic is, beginner's book or whatever personal encouragement for me, please, let me know.