You need to look into LGPL further. You do NOT have to pay for licensing if you want to sell a program later!
I will put in a huge word for Qt here. I’ve been using it for the last 5-6 years at work for cross platform development. Previous to this, I had used Microsoft MFC and also some other cross platform libraries. Qt is by far the best thought out and most comprehensive solution, and it’s now free. I’ve convinced a few people to spend a weekend with Qt and a ‘programming with Qt’ book, and they’ve all been able to get started quickly. Certainly much faster than with straight windows calls or MFC. It was written by programmers for programmers and it shows in the logical design. The extras, such as networking, xml, database, and so on are just great extras.
Visual Studio is an awesome IDE in my opinion, regardless if you’re just doing console work or doing GUI stuff. It also has MSDN help built directly into it, which is extremely useful while doing Windows API work. You can the express version for free at http://www.microsoft.com/express/download/