I'll just leave this link because I really liked it back then:
Basic Korean Sentence Structures:
http://www.howtostudykorean.com/unit1/unit-1-lessons-1-8/unit-1-lesson-1/
I agree with Joshua. I've been using the Korean grammar in Use books which I find really helpful. In addition, I practice 3 to 5 hours a week with my languages partners and I try to watch some korean programs with english subtitles.
Twochois.com have some great books (including those from Seogang and Yonsei I think) maybe you can find something that will interest you there :)
I think the best way to learn language is talking with natives. I am learning English at language school and italki recently and I found it really helpful whenever I speak not natural sentence they correct me immediately.
So, find someone who's a native speaker of Korean near your place. Or if you need someone to do language exchange online, maybe we can help each other. Good luck!