There are many traditions for a shiva home and we will list some - though certainly not all - of them here. First and foremost, as much as the immediate mourners (spouse, siblings, children, parents) may feel like doing things around the house to help, traditionally they are not supposed to be in the role of host or hostess. They should be free to share memories of their loved one, as an important part of grieving.
It is customary to leave the door unlocked so family does not have to greet people at the door, and it is traditional to enter without knocking. If you are not comfortable with leaving the door unlocked, delegate a non-family member to let people in.