The number one question I hear is usually how to you make sure they are reading; how do you assess it. I get it! I was there once as well but Bryce Hedstrom would always remind me to KISS (Keep It Simple Silly.) The short answer is you don't. Now maybe you have one of those classes that you HAVE to give a test to, either because of behavior or admin, but for the typical FVR activity it is not tested.
That's easy: your high flyers are on task and your other students are just staring at the book. At first. You have to get them to buy into it and you have to model. A good way to start is by having the class read a short story together. You could read the first paragraph, pause to answer their questions, randomly call on someone to translate, and the read the next paragraph.
If I have a kid that tells me he hates to read I tell him that just means he hasn't found the right book yet. I will ask him (or her) about his likes and his hobbies and what interests him and try to find something. Most FVR material is fiction and some students just aren't that into fiction. Bryce Hedstrom has a book of non-fiction material called Conexiones that usually goes over well with them. I cut out all the pages of the book and laminated them since it's just a little pricey at $30 to buy 5 of them.
It depends on the level and on your kids. I start my level 1 students at 5 minutes and, maybe, will get up to 10. I start my level 4 students at 10 minutes and we stay there the whole year unless they ask me for more time.
Actually I do! After a few weeks I put them into groups of 4 kids who are reading the same book and let them work together. I almost didn't because I was sure they would just goof off but they were all on task and seemed to really enjoy reading their book out loud. I had them read it out loud in English to check for comprehension and to not have to listen to their midwestern Spanish accent. LOL