BJN: Getting a "neutral" white balance is important if you're shooting products or artwork and need the color rendition to be true to a particular daylight color balance. But for the vast majority of images, you don't want to neutralize color to render a neutral gray. Warm or cold ambient lighting is often what makes an image work. Most photographers shouldn't bother with color targets and white balance lens caps. They're specialty tools and if you don't know that you need them for you probably don't need them at all.
Yes and no. Most of raw converters use colour profiles that assume neutral white balance; and often it is better to start with a neutral image and add the feel of light at a later stage, in a controllable manner.
IMHO Mr. Sharma's book together with Mr. Rodney's "Color Management for Photographers: Hands on Techniques for Photoshop Users" deserve the first place; while ColorThink Pro should be the second most important tool, as some profile analysis, quality control, and comparison are very obviously needed. BabelColor and basICColor are very worth a special mention.
Matthew Miller: A new alternative for the adventurous, especially for those of you who value openness: http://www.hughski.com/
Based on TCS3200?