As a young and overwhelmed newlywed twenty-some years ago, I read The Only Investment Guide You'll Ever Need. It was clear, fun to read, and full of good advice. I was recently surprised to see it is still in print, revised and updated.
If you're already the sort of person who reads personal finance books, it won't be the only one you'll read, but it may be the one that holds up the best over time. Tips such as "invest" in staples such as coffee when they are cheap and ride out times of inflated prices by using your surplus are as useful today as they were in 1978. (Although if I remember, Tobias used canned tuna as the example in the earlier editions, and now uses cases of wine to illustrate the point.)
Tobias has updated the book to include investment advice that we never considered in 1978. He includes tips on how to find the best online air fares, when and when not to use eBay, TiVo, and reverse mortgages. He has some simple and effective ideas on how to make Social Security viable for the foreseeable future (without resorting to privitization). He gives specific advice to couples who are married and couples who aren't or who can't be.
One of my favorite sections is on what to do if you win the lottery. How many long drives have I passed by planning that very thing? (My first step: get an unlisted phone number.) Tobias's advice on this unlikely event is excellent, especially step 5b.) Don't buy a boat.