The public Magento Wiki is a mess of mixed content, but it’s worth subscribing to the RSS feed of recent changes. The more dedicated members of the community tend to keep their articles up to date on changes to Community Edition, and it can sometimes save you from being blindsided when considering a new version.
Magento Wiki
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Frustrated by Magento? Then you’ll love
Commerce Bug,
the must have debugging extension for anyone using Magento. Whether you’re just starting out or you’re a seasoned pro, Commerce Bug will save you and your team hours everyday. Grab a copy and start working with Magento instead of against it.
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Programming Quickies
Quick dispatches from the life of a working programmer.