1) Ask a lot of questions. You know what they say about assumptions!
2) If you are in doubt consider hiring an installer. If you do hire an installer, have them measure your windows. Whoever installs your windows should be the one who measures them. Each installer has their own way of installing windows. It is not safe to assume that the measurements given to you by one installer will match the measurements another installer will take.
3) Industry standard calls out windows WIDTH X HEIGHT. Switching these measurements is a recipe for disaster.
4) When determining how a window opens go outside. If a horizontal slider opens from left to right when viewed from the outside it is an XO (X indicates the opening side and O indicates the non-opening side). If it opens right to left it is an OX.
5) Pictures help. Take pictures with your phone or camera or draw a picture.
6) If possible go outside to measure the windows. It is likely the inside of your window frame is covered by sheet rock and liner material which will produce smaller window sizes. The best measurements are taken from the outside with any trim removed so you can see the outer edge of the window frame.
If you have any additional questions, feel free to call Millwork Outlet at 425-432-