Ask Yourself: What Chemistry Do You Want to Learn?First, identify what it is you want to learn. How to calculate pH? All about acids and bases? High school chemistry? Organic? If you try to learn everything that is encompassed by the general term "chemistry" you will have a hard time narrowing your options and focusing your studies.
Ask Yourself: Do You Need a Teacher?If this answer to this question is "yes" then your best bet would be to take an online chemistry class. Online chemistry classes are set up much like traditional lectures, except the instructor is located somewhere else.
Ask Yourself: Free or Paid? For Credit or Yourself?Do you need to take chemistry to satisfy a degree or graduation requirement? If so, expect to pay for your education. There are free lectures available online, too, but they may not satisfy requirements for schools or businesses.
Conduct an Online SearchUnless you already have an online class lined up, you will need to conduct an internet search to find a chemistry class. Go to a search engine (e.g., Google) and type in exactly what you are seeking. For example, if you are seeking to learn organic chemistry, try a search like, "learn organic chemistry" or "organic chemistry". Click on the links and see what you get.
Narrow Down Your ChoicesThere is no harm in learning from more than one website, but don't learn from so many different places that you lose your direction. Seek a site that offers the information you seek and is written by someone with respectable credentials.
You'll be able to gauge your progress if you use a site that offers online quizzes and summaries so that you can see how well you have mastered new chemistry concepts.