Hi, Alice. There are some questions that have to be answered first. How much of the paint is flaking off? How much build-up of old paint do you have? How old is the house?
The reason is that you have 2 choices; stripping, and sanding. Stripping is much more work and expense but might be warranted if you have a lot to do and already have a heavy build-up. Sanding is fine for small areas with little present build-up but there is a consideration for lead paint. Let us know. Henry in MI