DO NOT GAMBLE!
That's right. You heard me. Not even a little.
Las Vegas makes its money on the tens of thousands who flock to the town daily, much like lambs to the slaughter (or more accurately: sheep to be shorn), money in hand, ready and willing to give it away. They stage fabulous free shows, legendary bargain meals, pay the salaries of tens of thousands of employees, and house the whole thing in palaces of decadent opulence. And make a tidy profit, besides: all paid for by patsies and their paychecks. Do not participate!

SO WHAT THE HELL'S THE POINT, THEN?
The notion of going to Las Vegas and not gambling sounds sort of like going to the pool and not getting wet, but let me explain: remember all of that fabulous stuff that gambling idiots pay for? THAT'S what you should go for. Think about it. What do you look for in a vacation resort: Luxurious accommodations? Great food? Extravagant entertainment? Great Nightlife? Relaxation by a pool the size of Lake Michigan? Well, ignore the casinos and you just described Las Vegas. Better still: because the gambling-schmucks-with-money are subsidizing the whole thing, your vacation is a fraction of the usual price. So enjoy!

KNOWLEDGE IS POWER
Most people have a lousy time in Vegas. They stand in long lines for lousy food. They lose all their money. They are usually lost, bewildered, and confused. More than at any other tourist destination, information is the key to having a good time. People tend to enjoy this town much more on their second trip (provided they every come back). Really lousy deals exists side-by-side with phenomenal values. It's sort of like a mousetrap - the cheese is free, but only if you know how the trap works.

FOOD FOR THOUGHT
You can have some of the best meals on the planet in Vegas, you can also have some of the worst. Just because you see a $3.99 surf-and-turf advertised, doesn't mean you want to wait in line for an hour, get lousy service, just so you can gag down some nasty food. On the other hand, the town is loaded with great food at low prices. Likewise, Las Vegas buffets are legendary, but so are the lines for them around mealtime. Detailed research is called for, but here are some handy rules-of-thumb:
1. Avoid peak hours, especially for buffets. Since you'll be eating twice your normal intake anyway, you might consider eating only two meals a day, eating a late lunch or early dinner, around 3 or 4 pm.
2. Go to local's casinos. The food values are terrific, and the lines shorter. Station Casinos, Fiesta, Orleans, Reserve, and Sam's Town are all good bets.
3. When in doubt: coffee shop. Casino "coffee shops" are so-named only because they are open 24hrs. They actually tend to offer a great variety of very good food, often in elegant settings. Their lines tend to be short and prices reasonable.
4. Avoid "gourmet rooms". Many upper-end Vegas Strip restaurants are heavily overpriced, and not all that "gourmet", either. They primarily exist to serve as "comped" rewards for "high-rollers", as well as a means of getting money out of anyone stupid enough to pay for a meal there.

THE AGONY OF THE FEET
Think you're in shape? Not! I jog 10 miles per week, and I still have to be careful about blisters and leg aches when I'm in Vegas. The amount of walking one does there is incredible. Nearly all newbies come back with blisters. If you, like most of us, spend most of your day on your tush in front of your desk, you will have to be careful. Don't kid yourself: jogging is not walking; bicycling is not walking; weight-training is not walking. Unless you walk a lot, you are NOT in shape for this. My advice: pace yourself, bring two different pairs of comfy shoes (to spread the blisters around), and use transportation whenever possible. This is supposed to be a vacation; not a reenactment of the Bataan death march.

IT'S FARTHER THAN IT LOOKS
The unworldly scale of the world's largest hotels will constantly throw off your sense of perspective. Even something "just across the casino" can be a five-minute hike. Allow extra time to get just about everywhere. It's amazing how many first-timers take a look at the collection of megaresorts, and decide to "walk the strip". Folks, it's about 4 MILES from Mandalay Bay to the Stratosphere, and your route is cluttered with stoplights, as well as detours through labyrinth-like casinos. This is not a good way to spend a 110-degrees summer day. Mind you, getting around the strip on foot isn't too hard IF you are familiar with the network of monorails, moving sidewalks, buses and trams, but, as a newbie, you'll spend much of your time in futile searches for these conveniences.
No problem, you say. I'll just drive! Not on the strip, you won't - you'll idle, instead. Due to the horrendous traffic and distracted drivers (most are rubbernecking, like you), driving the strip is almost as slow as walking. Quick routes exist just to the east and west, but the strip itself is stressful mix of inattentive, disoriented, and inebriated tourists, mixed in with aggravated and aggressive cabbies. The best way the "see the strip", is to take the strip bus at night (when it's less crowded and the strip is aglow).