About credible sources
To address the concern of the investor of the bounty, I think the most credible sources are the books written for learning LaTeX and the manuals written for learning the packages. We can also say that the package and class writers are credible sources, since they have enough experience with LaTeX and TeX to create the packages. But the thing is, most of them learned LaTeX through different paths. Many people who use LaTeX don't have a programming background--like me. See for instance the post:
On learning LaTeX efficiently
Most of the other answers have already dealt with this. So I will divide my answer into sources available here in TeX.sx and my own experience for efficiently(?) learning LaTeX. I can't say though that I have been learning it efficiently enough. I still consider myself a newbie.
For related reading
There have been related posts regarding your question. Look for Linked and Related at the right sidebar, notably the following:
Keks Dose mentioned about buying a book. You can see a list of free and commercial books and manuals in the following posts.
I agree with the other posts and comments to start with small examples that you can either copy-and-paste or manually type in a short time. Try deleting small numbers of characters from the code and compile, and see what happens. If an error occurs, ask yourself what happened wrong by deleting such characters. In some manuals, this strategy is sometimes used. Some examples are suggested in a recent post.
I agree with Harish Kumar. Coming from a non-programming, MS Word/OpenOffice background, I find that text-completion was a big help (but now somewhat irritating). You can see a big list of them from this post.
From a non-programming background, I am somewhat biased in favor of TeXMaker/TeXStudio. Some people, especially professional programmers would say
vim though, although they can be frustratingly hard to set up. Just see related posts regarding editors in this site
Give yourself time to learn
The truth of the matter is, I love to procrastinate. Learning LaTeX, for me, is a form of creative procrastination. Having said that, it is still possible to learn LaTeX efficiently without procrastinating.
I am a high school teacher and I have successfully taught some basic LaTeX to four of my students who have shown some willingness to learn LaTeX and alot some of their time to learn it. They use LaTeX to typeset their assignments (if they have time).
The following are the only things I demonstrated to them:
- Setting up the basic
source code, that one provided in Harish Kumar's answer.
- Setting up the margin using the
- Setting up list environments (
- Setting up equation environments. (My students are from an elective math class.)
The rest they learned on their own. But it will help you to know that they finished writing their math assignments by hand, ready for submission, before typesetting it in LaTeX. That way, they were doing the LaTeX part for fun (and for beautifully printed assignments). They don't get additional credits for typing it in LaTeX, but the same is true, too, if they typed it in MS Word.
Since essays are required often in high school and they are not that hard to type, I suggest you adapt the strategy mentioned above. Write them by hand first, then type them in LaTeX if you have the time. Or just for fun, even if you have already submitted your assignment but have a draft copy of it, type that in LaTeX if you have the time. The thing is, you should not try to learn it if you are rushing to submit what you are trying to learn it for. In that case, learning LaTeX becomes a burden and you might get discouraged.
The Danger of Copy-and-Paste Learning
I have mentioned above that for small code, you can copy-and-paste and tweak to learn what the code does. However, make sure that you understand what the code does, line by line. This might not help you now but it will in the future. At this point, try to explore what the default settings of the LaTeX classes
report have to offer. In most cases, you will be working with the
article class a lot.
What helps me when learning a new code is I comment on what each line does. I find this helpful especially coming from a non-programming background. There are instances, too, that copy-and-paste approach introduces invisible characters that introduce errors. In the long run, typing the code character-by-character, line-by-line makes you think more about what goes into your code and what fix you can do in instances of errors.
Some more advice
Just as the other posts had mentioned, there will be a lot of frustrations ahead. Especially when there is an error that you can't easily solve or a style that you can't easily implement. Treat these instances as learning opportunities. Just keep using LaTeX. Like any new skill, it takes time before you feel that using it is a natural thing. And there are a lot of help now to be had. In my case, there is no local TeX group I can join so I joined this site instead. And I learned a lot in the short time that I am here. And I am still learning a lot. I think I learned more in five months about LaTeX more than I have learned in the three years of using it before joining here. So use LaTeX, read the manuals/books, and ask if you have a problem that you can't solve on your own. And your learning will be tremendous.