Barbecues are pretty easy to transport as they are quite robust, but there are a few things you can do to make life a little easier.
Empty the barbecue out
When transporting a barbecue make sure the actual bbq is emptied out. This means taking out any charcoal or cooking racks they may move about during the transport and this will therefore reduce the risk of any damage. Also make sure any external moving parts are secured such as the lid of the barbecue, this can be done using rope or even tape to secure the lid from opening and shutting during the move.
Protecting the barbecue
If you wish to add extra protection to the barbecue then wrap the barbecue in blankets and secure, this will hopefully stop any exterior damage from occurring. You could also dismantle the barbecue from the stand which would allow you to fully secure the actual barbecue itself.
Gas cylinder transport
Transporting gas can be subject to certain regulations so it is important to check with the transportation company you are using to confirm whether they can transport gas cylinders or not. If they can they should be able to give you more advice on how theses should be correctly transported. If the transportation company cannot take the bbq gas cylinder you can contact the cylinder manufacturer (eg Calor) about whether the cylinders can be transported by yourself and how best to do this.