My advice is get the book Starting Strength by Mark Rippetoe. He:

• introduces 6 major lifts
• explains why these are the lifts you should be doing
• explains in detail the proper way to perform the lifts with common mistakes, how to spot them, and how to fix them
• explains why, biomechanically, the suggested form is the proper form
• explains how to put these lifts together into a fitness program, and when to stop that program and move on to something else

I was skeptical of the proposed program because I had already been lifting for a couple years, and I found a lot of the suggestions unintuitive. However, after two independent sources told me it was a good program, I started doing it. After 8 weeks I was able to bench press 77.5kg, whereas before I had been stuck for a long time around 70kg. All of the lifts also felt more comfortable / safer than they had before (due to changing my form to match the guidelines in the book).

There is also a Starting Strength Wiki that has lots of good videos / summaries of the information in the book (but the book is way more details / useful, at least for having proper lifting form).