Yes, actually! I wrote an introductory Marxist-Leninist reading list, you can skip straight to the "imperialism" section. It'll be a bit difficult to jump straight there without the other sections, but it won't be impossible. If you only read one, it should be Lenin's Imperialism, The Highest Stage of Capitalism | Audiobook, which is by far the most clear and important work on the subject. The only problem is that imperialism has developed quite a lot since Lenin wrote it, and the US Empire is now unquestionably the top dog. For more on that, I recommend Michael Hudson's Super-Imperialism: The Origin and Fundamentals of U.S. World Dominance.

If you only want a quick overview, though, Prolewiki's article on imperialism is really good by itself.