There are many words that I'm having trouble pronouncing :/
Watch this starting at 5:03... http://youtu.be/vHe7f_L7S2Q?t=5m3s
Ton of letter combinations, not so many sounds.
The thing that has helped me the most is learning the different sounds of the swedish alphabet. Many of the sounds of a foreign language do not exist in our own, so it's necessary to distinguish them :) Learn that alphabet! I promise it works!
The main sound not found in English is the sj-sound. The others have close approximates that show up in common words (though which words exactly may depend on your dialect).
Regarding the pronunciation of vowels and the concept of vowel and consonant length, there are 3 videos in this thread that could be helpful: https://www.duolingo.com/comment/6502614
Tack så mycket!