I'm not an English teacher, but I do sleep next to one every night...
She teaches senior lit. That's Brit lit in the CA system. I'll try to help you out with stuff that she has had to deal with over the years.
First, discipline. Being a sub is a rough, thankless job. One thing that helps is having an administration willing to back up the teachers and not give in to parental whining. She's taught in both situations, and the former is far preferable to the latter from the teacher's perspective.
You'll have to assert yourself. Note that it is much easier to be a complete hardass from day one, and let the kids earn you easing up on their behavior than to try to be the "nice guy" and have to ramp up the discipline after things start to get out of hand. Building a reputation helps, but you don't have that luxury as a sub. You will have to choose a "sacrificial lamb" -- typically the first student who steps out of line -- and bring the wrath of God down upon them in a very public fashion. Just make sure it's not over something stupid, make it over something worth the trip to the ass-prin's office.
Next, grading. English is a notoriously difficult subject in this regard, as it is easy to get way over your head in terms of correcting papers. The good ones often burn out trying to grade everything. When you're spending 15 minutes per paper and you've got 60 papers, that's 15 hours you're going to spend just on grading, not counting data entry. If you have more students, that only compounds the problem. Some stuff just has to get graded "holistically", meaning did they do some minimum amount of work. Sweating grammar and/or spelling on every assignment will kill you.
If the school offers it (and you are able to come back for another year) use your best former students or people recommended by former students that you trust as aides. They can do data entry, or grade standardized homework for you, freeing you up to do other things.
Now, as for classroom activities, my wife likes to break things up into chunks of time. Her school is on block scheduling, so she has (3) 90 minute periods a day, no prep. If your school does the 6 or 7 periods a day thing, you may need to adjust or alternate activities every other day or something. First, she has what's known as 'SSR', or silent sustained reading. They do something like 20 minutes a day, most days. She makes them keep a journal.
You have to be passionate about your subject, or your kids will get that you're faking interest in the subject matter as well. Luckily, my wife is a total Shakespeare junkie. She not only gets into the reading material, but also into the time period. She is constantly bringing in outside reference material that helps the kids understand what else was going on when the piece was written. She's shown things like Steven Colbert's performance at the White House correspondent's dinner when discussing satire. She's shown the episode of South Park where Terrance does Canadian Shakespeare and they do a line-for-line reading of the death scene in Hamlet -- with the addition of "buddy" or "guy" here and there. She shows the Simpson's episode where James Earl Jones reads "The Raven" every year at Halloween. She does 1984 and shows "The Lives of Others" along with. She's discarded stuff from the textbooks by certain authors because she knows of other work by that author that the kids will like more. She ditched one of the Canterbury Tales (I forget which) and substituted the bawdy "Miller's Tale" instead because she knows the kids will relate to it better.
Ultimately curriculum will be a mix of what's dictated from on high, and what you bring to the classroom. As a beginning teacher, you'll need to keep your head down and attract very little attention to yourself. Once you're tenured, you can push the envelope a little more.
As for class discussions... it's hit or miss depending on your class and your relationship with the kids. Some classes will interact wonderfully, and the discussions will be in-depth and productive. Other classes will be like pulling teeth just to get a few comments. This isn't necessarily a reflection on you or your teaching ability. As the kids get to know you, they'll be more comfortable opening up. My wife tends not to punish swears or obnoxious behavior that's just damn funny. If it's done right, the rules can be broken, and the kids appreciate that. They also know they better get it right, or she'll have their asses. She rarely has discipline problems.
Hope this helps somewhat. It takes a lot of finding your own way, and customizing the lessons others are willing to let you have. It will take you several years just to get your systems in place and functioning smoothly. And you'll likely be bumped from grade to grade in the beginning, which means that until you've got lessons for all the high school grades, you'll constantly be re-inventing the wheel. But that's just how it goes. Don't give up.
