There are as many ways to take notes as there are to skin a cat...ultimately, you'll need to find the method that works best for you. In the meantime, take the opportunity to learn different note-taking techniques and tools by experimenting with different ones.
Taking notes from a text may start with highlighting, but only the most important bits! Highlight as you're reading through the first time--then go back and only re-read the parts you highlighted. If you can't highlight the text (maybe because it's a library book?), take notes on paper.
Writing out notes by hand has many benefits. Studies show that we remember what we write, and make more connections between ideas. This is in part because when we write, we are summarizing what we hear--that takes more brain power!
When we type notes, we tend to either cut & paste, or transcribe word for word--that's not notetaking. You're copying more words than you need, which means more information to plow back through later; you're not really thinking about what you're copying, so you're not making connections between ideas and concepts.
If you really want to take notes via computer, make sure you're A) reading the content all the way through before taking ANY notes and B) taking actual notes--no copy & pasting, but recording the MOST IMPORTANT information in your own words (use quotation marks when necessary).
Using visual clues to visualize meaning, show relationships between pieces of information, or organize your thoughts as you take notes.
I still take notes in a mostly outline format, the way my 8th grade Social Studies taught us. It works for me! You may be required to take notes using the Cornell method--both are good to know how to do!
With an outline format, you are listing a main idea or theme, and following it with subtopics--may bulleted, maybe just indented. (Maybe, like Mr. Smith taught us, with Roman numerals!)
I use certain symbols to mark ideas or information that don't fit neatly in with a topic--stars are for cool ideas I might want to use; in the margins, I write the names of tools and resources I don't want to forget.
The Cornell method is an excellent way to take notes, especially for studying for tests and exams. It's not unlike the outline method--it's just a different format.
The left hand, slimmer column is for putting main ideas, themes, keywords, and/or questions. The bulk of the information goes in the larger, right hand column--still only summarizing. (When studying for a test, you'd cover up the right hand column, and answer the questions for define the keywords in the left column.)
At the top of the page, you'd put all the information about your source--or if it's a class lesson or lab, the date and description.
At the bottom is where you write your reflection, summarizing all of the concepts, making connections between data points, and adding your own thoughts.
There are lots of great tools to use to take notes digitally. You've already seen Padlet and Google Keep in action, a little bit--feel free to experiment with those. Google Docs is great for notetaking, too.
Diigo is a social bookmarking site that also allows you to take notes with its Outlining feature. Any pages you bookmark and tag can be added to My Outliners--from there, you can open the site on the same page, highlight as you read through, and add notes in outline format alongside. This is a great tool because, not only can you take your notes digitally with the website open, but you'll never forget your sources!
Evernote is a popular one that works on both tablets and laptops (you can sign up with your school Google account); Notability is another one, but only works on iOS devices.
The thing to remember is to NOT CUT & PASTE! This is crucial! You won't retain anything, and you're actually making more work for yourself. You also run the risk of earning a bad grade because of unintentional plagiarism.
Try using the speech-to-text feature in these platforms, like Read & Write for Google, to see if speaking your notes helps you develop better habits.