Your willingness to help.
Some students are afraid to ask for help. Telling them that you want and expect them to can help them get over that hurdle.
What a successful student does.
Although you can’t model success in the classroom, you can identify it.
“A successful student attends all classes.”
“A successful student arrives on time.”
“A successful student does the homework.”
“A successful student asks questions in a timely manner.”
What facilities and resources are available for additional help
Make sure you identify your office and your office hours.
Give the room number of the writing lab. If the hours are simple, give those as well.
Give the phone number for and the room number of the tutoring center. Again, if hours are simple, give those as well.
Questions are good
Some students will not stop asking questions, whether they need to or not. But most students are afraid to be embarrassed by asking a question. You need to set a policy, and act on it, that encourages questions.
You could even ask questions yourself and have the students answer, using the method identified in How to Tell Immediately if Your Class is Getting It.