Nancy in Louisiana

I just purchased an new 18" Janome Artistic sit-down long arm machine and had thread questions. I'm very new to long-arm quilting. I got tired of wrestling quilts on my regular machine and don't have room for a frame. I opted for the sit-down model. I doubt I will be doing anything extremely fancy for quite awhile and usually don't make anything larger than a twin size. I am very interested in hearing your recommendations and experiences on thread use. What kind is best (brand and weight)? Do you use different weights for top and bobbin? What size spool is best to buy -- or, can you quilt the top of a lap size quilt using just a 500-yd spool? I'd hate to have to buy a 2,000 yd cone if I only need it for one quilt top.

I was amazed at how pricey some of the threads were. Since I'm just starting out, I only purchased black and white. What would be next best colors to buy? Have you used any of Connecting Threads products in a long-arm. Do you have any favorite sources for thread that you would recommend?

Any hints or tips you can give me would be greatly appreciated. Also, are there any other helpful tools I should be on the look-out for?