I have heard that the cab ride from the airport to Downtown can range in price a great deal depending on the route. What is the best way to tell the Cabbie how I want him to drive from the airport to The Golden Nugget without sounding like a first timer?
Also-husband will be in classes for 8 hours each day. What are safe, fun things for me to do while he is away? Again-never been there (have 4 days)
and I dont gamble.

Just tell him the Golden Nugget and step on it. No matter how they go, you're only talking a few bucks.

Pumpy is right--cab rides aren't that expensive in Vegas.

Things you can do: The Golden Nugget has a pool and a spa. Just walking up and down Fremont St. and checking out the scene downtown can take a couple hours.

Take a cab to the Strip and explore there. Every single resort has something fun and different to offer. You can kill a whole day walking around the strip, checking out all the resorts and their attractions.

You could try one of the nicer spas on the Strip if you're into that. Qua at Caesar's is new.

Eat lunch at one of the resort buffets.

Shop, shop, shop--LV has everything and tons of it.

Hop on the Deuce bus, buy a $5 day pass and you can hop on hop off all afternoon as it rides up and down the strip and stops at the different themed resorts. thedeucelasvegas.com

GrayLine has tours of Vegas, or tours to Hoover dam etc. There is an 8 hour deluxe tour of Las Vegas that also gets out to Red Rock Canyon. grayline.com

First, be sure you are not confusing "downtown" with "the strip". They are two different areas.

For a cab ride to the GN, which is downtown, you might expect to pay 20-25 dollars plus tip. The cab driver should avoid travelling to the downtown area via the strip, as the traffic will increase the time and the fare. The cab driver will most likely take the airport tunnel to I-215, then connect to I-15 and head north to the downtown area.

For a cheaper option, consider the bell trans airport shuttle. It may stop at other hotels before reaching yours, but if they have a dedicated downtown shuttle, all the other hotels are very close and shouldn't delay you too much. You can find info at this website-

http://www.bell-trans.com/vehicle_airport_shuttle.htm

Consider a rental car. If you can find a car in the $20-25 per day range, you can avoid waiting for buses and taxis. All resorts offer free parking garages as well as free valet parking. (If you use valet, be sure to tip the attendant when you pick your car up after your visit to the hotel.)

Add the cost of a cab ride to the GN, and one back to the airport with the cost of other transportation during your stay and you should be about even if you rent your own car.