First timer questions

I am about to cook my first ribs on a weber kettle charcoal g. that a friend gave me.( have used a gas grill for years) Anyway, how many charcoal briquets should I add in order to optain a low temp?? Also, what is a good moping solution? And, do I put the wood chips,(after soaking) directly on the coals, or construct a foil smoker box? I plan NOT to boil the ribs and to use a dry rub the night before. Thanks

Don't ever boil ribs. Unless you're making soup. Start with 12 briquettes if you've got to use them. (You'll have better luck with lump charcoal. Hotter fire, and no chemicals in it, giving you more flavor.) Add more as necessary. Put your chips (chunks will smoke longer) right on the fire. Mop? I don't mop ribs, and wouldn't recommend it. If you really want to, I'm sure any of Steve's mops would work fine.
Tips: Allow the ribs to come up to room temperature before bbq'ing.
Use indirect heat. Don't peek, as it prolongs cooking time. Don't rush it either. 3-1/2 to 5 hours is fairly common.
Any sauce, should be put on during the last 20 minutes.
Happy eating.

As far as how much fuel to use you will need to experiment with your grill - even if others have the same grill your conditions are not the same as others. As far as a mop sauce I simply use Apple Cider in a spray bottle and mist the ribs every 1.5 - 2 hours when I check the temperature to see if I need to add fuel. As far as the type of fuel I would suggest lump charcoal like the other poster. I use a smoker with an offset firebox and I start with very hot lump charcoal (invest in a chimney starter if you do not have one - don't use lighter fluid unless you want to taste the chemicals in you food) and then I add either hickory or apple logs for smoke and additional heat.

I cook exclusively on Weber charcoal grills. The best thing is to have divider rails and place half a chimney of lump on one side and half on the other. Put your drip pan between the rails and your ribs over the drip pan. Set your vents to about 50% on top and bottom and add some coals every hour. Chips go right on the hot coals, although I prefer chunks myself. A hinged cooking grate helps facilitate this even more so.

Congratulations on cooking over a real fire!

A lot of good responses here, and I agree with most points said. I use my Webber Kettle exclusively. The one thing that you didn't mention is the size of the kettle- that would determine the amount of charcoal to use. I actually use a full chimney starter (22.5" kettle)of charcoal-lump preferred, and I control the heat with the vents- this will give you plenty of cooking time before needing to replenish the coals. An oven thermometer placed right on the grill rack will determine the actual cooking temp. If you can- invest in one of those remote temp sensors- it has a probe on a long metal wire that connects to a unit outside of the grill. This way you can always see the cooking temp without raising the lid. It will also transmit the temp to a remote unit so you don't even need to be near the grill i.e. sitting on the lazyboy watching a football game If you are using lump charcoal, you can add that as needed directly on top of the ones in the grill. If you are using store bought, start them in a chimney starter (or a portable grill works well) and get them nice and grey before adding. As mentioned apple cider is a very popular mop. Wood chips or chunks right on the coals. Before you apply your rub the night before, put an even coating of mustard on the ribs- this will give the ribs a nice crusty tecture with some snap to em. Good Luck

FYI remote temp gauge:
http://www.barbecue-store.com/tempdetective701.htm