Hi, if you have sanded it all down and filled any bits that need doing then you are ready to start. First of all you will need to prime any bare bits, then give it 1 or 2 undercoats depending on how it covers followed by a topcoat ie gloss, eggshell. In between coats I would give it a very light sand with fine sandpaper to remove any little bits that may have found their way on to it and if you want a really bit free finish get a tack cloth and wipe that over it before putting on the finish coat. Make sure you use a decent paint brush as this can make all the difference. I always use Hamilton Perfection brushes myself, others on here would say to use Purdy. It depends on how much you want to spend on them. One final thing would be that if you think any of the surfaces are greasy or dirty then wash them off with Sugar Soap before putting any paint on as paint will not adhere properly to dirt of any kind.
The quality of the paint job on the skirting boards will mostly depend on the finish of the board, if it has a low quality or rough finish, the painting is going to be very difficult. the best way to achieve this is to sand down the profile prior to priming and afterwards, and before painting.