Buy the fruit, prepare it by washing and then cutting/peeling, then dice into chunks, dump into a steamer and steam for 5 minutes. After steaming, toss into a blender and blend. Alternatively, if your baby is older than 7 months, you can give fresh fruit by mashing or chopping it up into small bite sizes.
Cooking fruit is important for babies below 7 months as it makes the sugars easier to digest. In fact, I still give Eva cooked fruit puree - it's very French (they call them compotes).