From Paul Brians’ fine book Common Errors in English Usage (which he, amazingly, gives away at no charge at the Washington State University website, among other places), here is a worksheet on the proper use of here’s (the contraction of here is) and here are. This is full-page worksheet with a short reading explaining how to use these words and phrases (the predicate noun, plural or singular, governs the verb number) and ten modified cloze exercises.
If you find typos in this document, I would appreciate a notification. And, as always, if you find this material useful in your practice, I would be grateful to hear what you think of it. I seek your peer review.