Hi
In Belgium you can land at a private landing site with permission from the landowner if you only need to land once or twice on the same day.
If you need to make more regular landings like for plesure flying then you need to register the site for the day, Which requires a site inspection and detailed drawings and some maps of the site with takeoff & landing directions etc, If you need to make multiple landings then you also need permisson from the town hall.
For NOTAMS & FLIGHT PLANS check out
www.belgocontrol.be or phone 003222062540.
In the Flemish (Dutch) speaking part of Belgium everyone will speak English but don't be suprized if they only speak French on the radio at Spa, Ive landed there quite a few times and normerly its a rush to get somone who speaks English. There is a nice hotel near by with a helipad The Ronnay
http://www.roannay.com