Good to see an updated list like this - some new things here for me to check at library.
I've always liked some of the articles at
FundAdvice.com - Home - the Merriman website - especially "The Ultimate Buy and Hold Strategy" and "Fine Tuning Your Asset Allocation". These two give a pretty good sense, with specific and fairly long term historic data, of the benefits of diversification among equity asset classes, as well as the long term "risk/reward" tradeoff for various equity/bond mixes. Merriman has updated these each year for last few years to reflect most recent data (turmoil).