Book on business...please help!

[Dinosaurintheoffice2]

Hello all, I'm back to work after 12 years at home (ill child, suddenly I was at home for 12 years and wondering where the time had gone)- now I find myself in an office environment where people are using lingo that I just don't understand!
I'm somehow in a mid to senior management role and I can do the job without any problems but I think I think a refresher in how people talk about business is needed- can anyone recommend a good book, online short course or free course that would give me a refresher on management structure, change delivery, strategic management etc.
I don't want to talk like these people but I do need to understand what they're talking about so I'd really appreciate any suggestions.
Thanks IA