There is a lot of really helpful information on this website. I like the user reviews of the lenses a lot, they really help the decision process.
The Pentax K-3 in-depth review was quite helpful because of it's added value compared to more regular camera reviews. E.g. the comparisons between other Pentax cameras, the new features compared to older models and the overall comprehensiveness of the review that made it really useful for me when I considered upgrading from a K-5 to my K-3.
Pentax K-3 Review - Introduction | PentaxForums.com Reviews Excellent work PF, highly appreciated
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You can find nikon/canon flash guides basically everywere but to my knowledge this is the only Pentax flash guide, and a good one at that:
Comprehensive Pentax P-TTL Flash Guide Updated - Articles and Tips | PentaxForums.com
I mention it second because it's already mentioned by other forum members and I discovered it after my flash purchase
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