I like my children to have a snack and relax a bit before diving into homework after school. I usually make them something pretty healthy and sit and talk with them when they come home. On the advice of a smarter woman than me, I make sure I am not distracted by emails, Facebook or the telephone. Electronics are turned off and I give them my undivided attention. We discuss whatever they want to talk about, usually their day at school, but not always. I don't set a timer, but within an hour of getting home they are usually ready to start their homework. If they need help organizing their time, we go over what's due soonest, what task can be accomplished quickest and what tests or quizzes are coming up soon. I also discuss their projects with them and have them bounce their ideas off of me. I might give a few suggestions or ask them questions that get them thinking a bit deeper on their topics.
Whenever they feel completely overwhelmed, I try to calm them down and I help them strategize their time. By staying calm and reassuring them that the work can and will get done, they calm down and relax.
This spring my youngest had trouble with getting all her work done and her grades plummeted immediately following her Bat Mitzvah. We didn't get angry with her, we reassured her she could and would do better and we were there to help her. We made a rule there was not going to be any TV or computer during the school week (Sunday night through Friday afternoon - Not just for her, but for the whole family. Within a few weeks she raised all her grades, my husband and I were better read and my eldest child got a ton of work done ahead of time for high school. I think we're going to start this practice up again come September. My daughter actually thanked me for making this rule.
We also make sure our kids take advantage of before and after school extra help. I guess we're very fortunate our school district offers plenty of extra help and teachers are insistent that children take advantage of it.