Book recommendation: protocols and recipes handbook for molecular biology / biochemistry
I know you are asking for books, but for up-to-date basic overview of how some methods work - I would try websites or YouTube instead of textbooks...
One good website is BiteSizeBio. They have their own section for 'how to articles' and educational webinars. Otherwise I would also try YouTube. If you search in YouTube for basic techniques like 'how does the ELISA method work?' or 'principles behind SDS-PAGE' then you will find a lot of instructional movies. There is also the 'the protein man's blog' for purification of proteins, some analysis but also some DNA things.