Read, Watch and Listen to Simultaneously
A good way to improve listening comprehension in English, once you know all the sounds of English, is to listen to blogs, broadcasts or videos that have both audio and text in English. This way, you have the spoken English reinforced by the written form. If you hear a word you do not quite recognize, you can look at the text and see the word; then, if you don't know the definition of the word, you can look it up in your dictionary. This is a great way to understand spoken English better and, at the same time, to build your vocabulary of words and idioms.
One of the best online resources for simultaneously watching, reading and listening to native English speakers is English Central. This resource includes videos, accompanied by line-by-line text, in three levels: easy, medium and hard. Once you sign up for a free account, you can access all the videos. As you watch a video, you see the text line-by-line on the screen. You can play back each line slowly to be able to understand the words more easily. This website is great for improving your listening comprehension, especially at an intermediate level.
For more advanced listening comprehension in English, try audio books. You can start by checking out some English classics from the public library (for example, Anne of Green Gables) and you can listen to the audio version of the book free online here while reading along in the book. This way, you are both listening and reading at the same time --seeing how the words are written, but also, more importantly, hearing how they sound when spoken.