OK, before I can get to making my rec room, I need to remoldel the washroom so now I'm tiling the floor and the walls inside the tub. I bought 4 sheets of DUROCK dry wall, I believe that I should insert the tub and fasten it to the studs, making sure my tub is level and whatnot, then hang the cement board (DUROCK) on top of the tub sill. At this point, what do I do with the vertical seams, and the horizontal seam along the tub? After that I would apply the thin-set and tile, grout the corners and such, then use caulking to meet the tiles with the tub. Is this correct? My colors are blue tile (10X13")cermic and the grout is grey. I guess after 3 days I seal the deal. This is my first go at tiling, I believe I can do it, however I only want to do it once, meaning correctly :) my floor tiles are porceline.

You should seal the vertical and horizontal seams in the Durock (excluding the tub to Durock seam) with mesh tape and the same setting material you use to set the tiles. You can caulk the seam at the tub / tile when your all done, just make sure you leave a 1/4" gap at the tub / Durock location.

You got good advice. Make sure your grout works with porcelein, not all do. I'd buy a pre-mixed stain proof grout.

The grout color is a delorean grey,