If your going to go with pre cut tiles, I would suggest geo-referencing your whole map image in Global Mapper, and then using it to cut your google map tiles (which will be correctly positioned, cut from best resolution out,and named to google's folder/tile name criteria), it will write your html as well,,,as long as you have a google map api code for the site that is going to display your map, to input, upon export from Global Mapper. The only thing you may have to change in the html is your server location as you will most likely save them to your harddrive, and that location is written into the .js portion of the html.
If your going to cut them on the fly, geo-ref as well, then as your map expands , just change the image your are cutting the tiles from and everything will remain accurate, like the icons you mentioned.
Then you can think about cutting image tiles for World Wind,Global Mapper does that too,,,3d maps on a globe.
You can probably get away with using precut tiles, google cuts them on the fly due to the size of the imagery/ hard drive space.

SeerBlue