For years, I follow Joel Spolsky in his blog. He has a very personal and convincing style of writing and opened my eyes on many topics.
Here is a very interesting talk in which he explains, why users always ask for simplicity although deep in their heart they want a lot of features. If you read his blog, there is probably nothing new in this talk, but it is very nicely presented.
Read the full article in his blog.
If you liked this one, you should definitely check out some more.
His recommendation to never through away your existing code and start from scratch was the reason I took a 20-year old Clipper-Program and kept it alive by turning it into a Harbour-Application.
I really enjoyed the articles about user interface design.
A classic is his post about Unicode, which gets recommended all over the web. It is 7 years old and back then UTF-8 was not as widespread. It is more important today than ever.