InfoWorld has a great article entitled The top 20 IT mistakes to avoid. Among my favorites on the countdown are:
- Mismanaging software development - "Simply put, a great programmer is 100 times more valuable than a regular programmer.” I think this goes for a lot of occupations, but is especially important in development and IT work
- Developing Web Apps for IE only - the browser wars are (sorta) back. Not everyone uses IE
- Clinging to prior solutions
- Violating the KISS principle
Its a well written article and the remaining mistakes are all worth reading and learning from.