And here Chris, I thought you'd be suggesting Body Flex--Body Magic by Anja Langer      

I can only add little to the great suggestions already posted, but basically the key to real, sustainable improvements in physique and your health is a genuine lifestyle change.  That said, start slow, set realistic goals and set yourselves up for success.

Personal trainers can be great or worthless, so I'd look carefully before spending your loot on one.  Common sense will get you further than most PTs.  Start of training 3 days a week doing cardio at least one of those days.  Keep your cardio to approx 20 minutes.  The key to intro cardio is to keep the pace at where you and your wife can hold a conversation together.  If you're outta breath, slow down.  A lot of weight training is counterintuitive, and this is one.

For weight training, try a push-pull split for starters.  Train Chest and Triceps on Monday, Legs and abs on Wednesday, and Back/shoulders and Biceps on Friday.

Eventually, you can really tweak your diet and dial it in, but gradual and consistent is more important.  Use common sense.  Eat 3 times a day, avoid sugar, soda, and what you already know isn't good for you.  Someone else said it, but steer clear of the supplement world save for protein powder.  Most of that stuff is overpriced snake oil.

Lastly (finally right?  When will this guy shut up?!?), ask a lot of questions and stay consistent.  Training with your wife will be a lot of fun too.  I had an ex-girlfriend that I told the same thing to, and she started coming to the gym with me and making some pretty freaky results for how little she really did, bursting buttons and all the rest.  She was a real natural. Unfortunately, it was what I wanted and not her, so she gave it up even though she really liked the way she looked and felt.  Just 2 cents from one buff-chick lover to another.  Good luck with your goals, make 'em specific stay consistent and ya can't lose.

Don't mention the "V-word" infront of Lingster.   He'd say that it's impossible for vegetarians to get buff, but as long as she eats plenty of pulses and takes protein powders she should be fine.  Maybe supplementation with essential amino acids, though supplements are not a good idea unless necessary.