This is a tough issue. It's very hard to come up with a solution that works for all sizes and resolutions, particularly when you throw in the fact that user may select large fonts.
I would try using Anchor and other properties such as Dock. A TextBox in single-line mode won't change its height but if you anchor the controls below it to Top/Left/Right/Bottom, they will stay with TextBox on the top and get taller when the form gets taller.
It's easiest if you have one control that can take up any extra space. For example, if you have a bunch of data entry fields at the top and then a big DataGridView taking up the rest of the form, the DataGridView can grow to fill up any extra space.
I think most applications that worry about this only really work on a couple of sizes. There's a "normal" size, a maximized size, and usually not too many others.
There are a few more thoughts at:
But as I said, it's a tough problem.
Check out my latest book:
"Expert One-on-One Visual Basic 2005 Design and Development"
Sign up for the free VB
Helper Newsletters at http://www.vb-helper.com/newsletter.html