If you cannot resize the form itself, then the property you need to change on the form is the FormBorderStyle property.
However, if you can resize the form, but the controls just stay in the same place, then there are a couple things you should look at adjusting. The first is the Dock property on a control. This is helpful to have a child completely fill to the entire parent size (fill) or to the top, right, bottom, or left of the parent control. When the parent resizes, then the control resizes as well. Docking is really only useful for panels and splitter containers and such. The next property that you need to look into is the Anchor property. Unlike Dock, the Anchor is bitwise, meaning that a control can be anchored to both the top and left, or the top, left and right, or just the left (or any combination of top, right, bottom, left). What the Anchor does is keep the edge of the control at the same distance from the edge of the parent no matter what. By default, everything is anchored to the top and left, so when you resize, they all stay put, (because the origin (0,0) is at the top left, so the controls always stay the same distance from it). So, if you take a textbox and anchor it to the top, right and left, then when you change the width of the form, the right side of the textbox will stay the same distance from the right side of the form (same as the left side does); this will cause the textbox to resize. Anchoring on all 4 sides will cause the control to resize it's height as well.
Open up the VS help and search for Dock and Anchor. They're properties that exist on all controls and will definitely get you going.