Ooh, good luck Lcy! What course are you a tutor for? What qualifications do you need?
From a student's perspective, I agree with a lot of what cb said.
Make it clear from the start when you are contactable, and how long you it will take you to reply. When assignments need to be marked, let students know if you will be turning them around in a couple of days or whether it will be 2 weeks - it makes a difference not to have to keep checking!
Circulate a list of people in your tutor group who are happy to give out their contact details - it helps students feel less isolated.
Give as many hand-outs as you can, or suggestions of where to look for things.
Know not only the course material really well, but also the assignments, which quite often change each year and so may have teething problems.
When marking, if you conclude that a student needs to say more on one aspect, but is up to the wordcount, suggest where they can chop bits out, don't just say 'good', 'good', 'good', 'but you should have mentioned xyz too' when they are at 2000 words
At turorials, spend a bit of time on introductions, don't just plough straight into the course. Oh, and tell students a week or so in advance what the tutorial will be about.
I have had good tutors and bad. This year it is a bad one, who isn't doing any of the above lol!
Best of luck and good on you for asking - that is a good start