Writing Skills

As Social Studies teachers working on students writing skills is not usually our main goal. However, I am a firm believer that English and Social Studies are two subjects that are easy to integrate and so should be. One of the most eye opening things for me lately is the difficulty many of the students I am interacting with have in essay writing. Some students do not seem to understand the basic principles in putting together their thoughts to form a composition. Students also appear to be intimidated by writing. I am not sure what to do. At this point in instructing high school upperclassmen do I cut my losses and leave the teaching of essay writing to the English teachers given the amount of material I have or do I take the time to inform students how to create an essay. I believe that I should perhaps inform students what I am expecting from them on an essay and what the state is expecting from them on their regents exams. This would probably be the best strategy when it comes to essay writing in social studies but that leads to a larger question. What about grammar and spelling mistakes? Do I take the time to correct those on written responses every time I see them or do I let it go because this is Social Studies and content and ideas is what matters? I feel that this is a position I will continue struggling with.