I'm sure you've heard the age old saying, "You are what you eat." My dad use to love saying it to me when I was eating "nerds". Most of us have heard it, yet we all know that it isn't true. Now if we change it to "You write what you read." It couldn't become more true. That's the reason that so many people - authors, agents, etc. - recommend reading the classics. They say that by reading the classics, you can improve your writing skills. And then 2 pages later they tell you not to write above a 6th grade reading level because that's the society that we live in. We have to write so that we are understood. So which is it? Do we want to mimick the classics, or write for 6th grade? It can't be both. Thus, I don't recommend reading Dickens. My recommendation is to read the books that your target audience reads - or at least books on that level. If you're writing for people who read the classics, then sure read the classics, but if you're writing for people who read modern-day writing, then read modern-day texts by authors who write in modern words (as apposed to modern-day writer's who are mimicking the classics).
Last year I started to go through a book study with some friends of mine. We were reading through Susan Hunt's "The True Woman", and everyone quit before we even got half way through it because they couldn't understand it. They had to read the same paragraph 20 times to figure out what the author was trying to say. We would have all gotten a lot more out of it if she would have just wrote what she meant in the first place... Another book that I reviewed for Tyndale house said that it was the Bible in plain English - yet I had to look up roughly one word on every page to find out what the definition of it was. That's not plain English. Plain English is using common, every-day words that the average reader will understand. My guess is that both of these authors read the classics - frequently. But their audience didn't. That's a problem. If you want your audience to understand you, read the books that they read. I'm not saying that you have to pick up the latest secular book that's full of word porn, but find books that are on the level of your target audience and read those. If you write for teens, go through the teen section at the Library. If you write for children, read children's books. If you write for average adult readers, read average adult books. If you are writing for the Puritans then by all means, read books written by the Puritans - just keep in mind that there aren't many (if any) left to read what you're writing, but you might be able to sell it to other people who like their books.