Hi Prof,
I've used the books you have and some others.
The Dummies book, once you get past the title, is pretty good (my teacher likes it too) and may be all you need to get started. I particularly appreciate the sections on setup. But the over all approach is sound and the examples are fun.
I also have the Serious book (talk about a change in marketing slant!) I think it's good for reference and also has a useful section on setup and related issues. But all those relentless pages of the notes in the modes get on my nerves. I get it already! I can't say I've used it much at all, but, as I said, when you want a good reference for scales, theory or technical stuff, it's in there. And I like the fact that they don't print a tab (that must be what separates the Serious from the Dummy). Sight reading is half the battle, the tab is a miserable crutch and this book won't let you cheat--a good thing.
I've also used the Electric Bass intro series by Dave Overthrow
It's a nice format and logical progression, but if you have the Dummies book you're OK, most of the beginner books cover the same ground.
Ed Friedland's books are all highly thought of, particularly his ones on Jazz, if you go in that direction.
I also got "The Bass Player Book" Same folks that brought you The Serious Bass Player, except this is more playful, though still plenty serious

I learnd theory from this one and I like the examples they use of the various styles and the tips they sneek into the text. I found I've gone back to it several times. And it's got lots of pictures and some history.
Welcome to the bass comunity
John