I haven't booked the flight yet but wondering how difficult it is to get to this airport. I will be staying in Brussels for 3 nights prior. If I do this what would be the best way to get there?
A few years ago, we had to catch an early morning flight from Charleroi, and although not ideal, it wasn't a big deal. We took the shuttle bus (look it up on Charleroi airport's website), which runs from the Midi station right to the airport. The ride was at least an hour or so, from my recollection, but that didn't present any comfort issues, since the bus was a big, comfortable tour-type bus. We took a taxi to the Midi station, but depending on when you're trying to catch the bus, you can just take public transportation.
The remote airports used by Ryanair generally are linked to the city they purport to serve by long distance buses, and Brussels is no exception.
Charleroi is considerably further from Brussels than the main BRU Brussels airport and is linked by that bus, while BRU is linked by a train.
Information about the bus is at the airport webpage at http://www.charleroi-airport.com/en/raccourcis-booking/brussels-city-shuttle/index.html and if you note it goes avery half hour and the "Stronly Recommend" that you take the bus 3 hours prior to departure.
If you do decide to use RyanAir please, please be absolutely sure that you really understand and comply with all of the hoops that they make you jump through and exactly what their rules are. If not you will likely find that nice cheap flight suddenly is very expensive. Such rules as size and weight of luggage, committing to the hold when you buy the ticket instead of at the airport, printing the boarding pass at home, credit card charges, change charges, matching to passport, and a myriad of others. Read all the conditions carefully. People who do are often happy. People who don't sometimes aren't.
And don't forget to bring the exact change for the toilet (LOL).
To add to Nigel, also be aware of the need to print your boarding pass before arriving at the airport. There is now a very heavy fee, almost a hundred bucks, if you don't.