This section is a work in progress. As I find helpful documents and sites and as I produce my own, I will post them here.
This link takes you to a useful site with choices of links for the newcomer: http://larryferlazzo.com/englishbeg.html
1. What do I do with the student who doesn't speak any English?
It helps to put yourself in their place; what would you want someone to do for you if you had to move to a completely new country and you weren't able to communicate? First, you can make them feel as comfortable as possible. One time in my career I took a new nonEnglish-speaking student to meet one of her teachers, and when I said to the teacher, "This is 'Kumiko' a new student in your class." The teacher didn't smile or even look at the student. Instead he said, "We'll see about that; I have 30 in this class already." Needless to say, that student did NOT feel very welcome- even if she didn't understand what he said. The teacher could have smiled and said, "Hello." Later he could have quietly said to me that he will need to check with the person who does schedules because some classes are more populated than others. Also, when you are learning a new language, you need someone who will speak clearly and more slowly so you have a chance to process what is being said. Use gestures and visuals and match what you are saying with what you point to.
2. How do I give him or her a grade?
At the very least the student should receive a "D" if they are putting forth effort to learn the material. Also keep in mind ways to help the student show what he or she has learned. For example, maybe he doesn't have the language to write a story or express what happened at the Boston Tea Party, but he might be able to draw what he knows. Why couldn't you grade that? Try to think of ways to grade what they know and NOT have their grade depend mostly on their language ability.
3. How and why should I modify the classroom tests?
First of all, when you give an exam, do you take away the glasses of students who can't see very well? No, they need the glasses to be able to read and understand the questions. Why wouldn't a teacher do what is necessary for a student learning the language? When you give an exam or quiz etc., there are actions you can take to help the student prepare. Give them a copy of the questions ahead of time so they can see how you word questions. Give them a word bank ahead of time so they know where to focus their study time. Allow them to use their notes or a student created glossary. If it's a multiple choice exam and there are many questions (that's a lot of reading and processing they have to do in a limited amount of time) - you can reduce the number of questions and / or reduce the number of choices. Think about how overwhelmed you would feel trying to succeed in multiple classes where you only understood the teacher a small percentage of the time and where (even though you copied notes and took them home to decipher them) you only understood a small percentage of the notes you copied. (for more ideas look at the section: "assessment modification ideas")
The main thing to keep in mind is: Are you giving them access to the curriculum? And are you really testing what they have learned? (or are you really testing their language ability)