There are tens of thousands of web pages devoted to our game. They range from single pages to hundreds of pages and can be intended for beginners(What is a trump suit?) to experts(How does Multi 2D work?).
The most efficient way to find what you want may be a search using your preferred search method. The search will almost certainly turn up several results. What is a trump suit and Multi 2D both turned up relevant results that would take hours to read.
So, here we list a few of the most important sites and then links to list of links.
Go for it.
Well, you should get the idea that the Web is full of bridge materials. Go Look for what you want!