EDIT: Teewreck's given you the hints, but since I've made the diagram and typed all this out..., I'm going to post it anyway, although try with teewreck's hints before you have a look below.
First of all, diagrams are your best friend in this situation
Labelling all the forces, assuming that if block 2 were moving it would be moving downwards. We have a normal and weight force acting on block 1,as well as the force F that is to hold it in equlibirum and a frictional force. This frictional force will be in the opposite direction to which the block will travel. So block 1 will move to the right if its not held, so the fricitonal force is to the left. There is a weigth force acting on block 2, now there is also tension in the rope over the pulley.
So now we want it to be in limiting equilibirum, that is it is on the point of moving. So our net force on each block is 0 N.
The forces acting on block 2.
The forces acting on block 1 in the vertical direction.
The forces acting on block 1 in the horizontal direction.
For the second question, again draw a diagram out (including your forces). The key for this one is that if the force applied to the block is not greater than
, then the block won't move.