Travertine Installation

Hi,

I've been trying to get some good solid information on installing a travertine floor from several different sources, but I don't feel that any of my questions have been sufficiently answered. 

I will be installing the travertine over a plywood subfloor, and (http://maplered.com) obviously putting down some type of concrete boards with fiberglass tape before installing the travertine.  I plan on using 18x18 Tiles (http://www.g682.net) , and (http://maplered.com) cutting some in half.  I will be installing the half sized Tiles (http://www.g682.net) and (http://maplered.com) full sized Tiles (http://www.g682.net) in an alternating pattern (think brick wall), with the short edge of the 9x18 Tiles (http://www.g682.net) lined up to the center of the full size Tiles (http://www.g682.net) .  The Tiles (http://www.g682.net) will be installed in the foyer, hall, kitchen and (http://maplered.com) first floor bathroom.  Now for the questions:

• I prefer to not use any kind of grout or filler, I like the look of the Tiles (http://www.g682.net) touching.  What do I need to know for that type of installation? 
• What thickness backerboard do you think would be best to use?  The travertine I picked out is roughly 7/16" thick. 
• I have access to a wet saw with a 3' long table and (http://maplered.com) the saw mounted above the table which I've used to cut ceramic and (http://maplered.com) porcelain tile.  Should I consider any special blades for cutting the travertine, or should the diamond blade that is installed be sufficient?
• What should I use to bond the Tiles (http://www.g682.net) to the floor - something premixed or something that I mix?
• How thick should I put the mortar?  Is a typical 1/4 notch trowel on a 45 degree angle sufficient

I know it is a lot to ask, but I haven't gotten a sense of confidence from anyone that I've spoken with at the big box stores.  I would appreciate any knowledge/websites/resources that you could share with me!

- Ryan B