My top three advice nuggets for a newbie teacher:
1. Classroom management.
What are your expectations and how are you going to make sure your students understand them? Research the age level you're working with and take time to understand the social and emotional characteristics associated with it. Model what you expect - it will take more than once. Check out The Responsive Classroom for a wealth of information related to children, classroom conduct and good teaching advice. I became familiar with the RC philosophy last year after my teaching partner attended a week-long training. It has changed my teaching life in so many ways!
2. Read new books.
Stay current with children's literature. Browse bookstores and visit the library - often. Visit blogs about children's literature to find out about new reads. As you become familiar with what is out in kidlit land, you'll have a wider variety of books to choose from for mentor texts. Here is my favorite blog to check out for information about books, A Year of Reading.
3. Take time for YOU!
Teacher's put a lot of pressure on themselves to be perfect. Don't loose sight of why you went into the profession in the first place. If you're worn down and tired, you won't be at your best for your kids - and kids can pick up on it. Eat right, get enough sleep and make time to do something FUN for yourself each weekend.