Mastering, proper Bit-Depth dithering

[magillagorilla]

I don't pretend to be a master at uhh.. mastering but I have several master copy shows I have sampled on my PC at 24bit 48k. I am using Sound Forge 7 and when I go to convert the bit depth (for CDA authoring) I am presented with the options:

Dither:
Half Rectangular
Rectangular
Triangular
Highpass Triangular
Gaussian

Noise Shaping:
High-pass Contour
Equal Loudness Contour

Anyone know what all that means? What is the best dithering method?

[jcrab66]

high triangular with high pass noise shaping is the cleanest, thats what i use