How to always be updated and manage information only useful to me? Don't want to waste time in my life.
I mean I don't want to waste my time reading ads and other things which aren't useful to me
I think your question is very bad phrased, but I will answer the question as:
How can I be updated and informed about latest technology in my field of interest?
Personally I think the most important is to start looking around for following items in your field of interest:
Even if you have gathered a number of interesting resources, you will still get to read things that are not of your interest. But over time, you will see an evolution in the resources you think are good and skip out those that are crap.
What resources are the best for you is up to you to find out! You have to build a community around you that enables you to gather important and usefull information.
But what is interesting for you, only you know!
Short of employing someone to filter everything for you, or refusing to accept anything that is not explicitly what you asked someone for, I'm not sure there is a way to achieve this. No-one wants to waste time but we all have to make best use of the resources that are available to us. Everything has the potential to be useful or useless, including ads, depending on your attitude toward them. Ads could be a distraction, or they may be a way to learn about what is available in the marketplace.
I suggest you lose the blinkers and get a large helping of reality. And if that sounds rather blunt, it's because by your definition, I have just "wasted" two minutes of my life answering a question that is not even slightly useful to me.
The problem with a question like this, is that how do you know what's useful or not, unless you've read it?
Sure, no one wants to read ads, but beyond that, you're the only one that can decide what's useful, so you just have to set up whatever filtering or information/input you feel comfortable with.
In a world of too much information and limited time you need to develop a personal filter system. This is a 3 step process:
Decide what's important You need to consciously decide what topics you are professionally and personally interested in. To help in selecting your topics take a look at your life goals and see where you have gaps in your knowledge. Information in of itself has limited value but applied to a goal becomes knowledge.
Filters Now you have an application for the information you can start filtering. Don't confuse tools (wiki, blogs, twitter, etc) with filtering. What you have to look for is curation, people who have real experience or who have taken the time (that you don't have) to uncover the valuable information relevant to your life goals
Don't worry about general knowledge or information not linked to a specific goal. If it's important it always finds you.
Review Nothing stays the same, your priorities change, goals are achieved or abandoned, source of knowledge go stale. You need to periodically review both why you are interested in a topic and the quality of the filters. Look to your exiting, curated, source for clues on improving your own filter.
That all said be sure to throw in a wild card every now and then. Again look for suggestions from people you respect (curation again) or inspiration from life.