There is nothing wrong with making astronomical observations for fun or in order to develop new skills and publishing these observations on a web site or in an amateur magazine is something that I would always encourage. Moving onto the next step, peer reviewed publication, is quite a leap upwards both in terms of the quality and quantity of the work involved but is definitely achievable.
But sooner or later you find yourself asking the question, “What astronomical observations can I make that would be of real value to the professionals?” The traditional, safe and non-controversial answer might include double star measurement or estimating the brightness of variable stars. There is just a tiny problem associated with both of these options – one is entirely wrong and the other is wrong at least 99 times out of 100!
The number of amateur astronomers I can bring to mind who have made double star observations in the last ten years that were subsequently found to be of value to the professionals is exactly zero. The situation with variable star observations is very little better. I have contributed many thousands of observations to the American Association of Variable Star Observers. While the number that have been used by professional astronomers is by no mean insignificant the number that have been used with full and detailed acknowledgement of their source is probably under 100.
In my experience it would be far better and far more honest to answer the question with the friendly warning that it is extremely unlikely that any observations you will make during your time in the amateur hobby will be of any value to the professionals. You should observe and report on objects that interest you and regard any professional use of your results as a bonus.