When I booked a motorhome for a month to travel around Canada with two children under-five, I was probably more excited than they were. But I was also a whole lot more worried: would we go stir crazy in such a small space? Would anyone get any sleep?

My concerns proved unfounded. Small children love campervans. They are magical playhouses on wheels; some even have special beds in the roof that you can only reach by ladder. Our children had a blast clambering down the steps and playing outside from early until late, and with all that fresh air we all got more sleep than we'd had in years.

We saw far more of the country than we would have done any other way, and far from being claustrophobic, our five-birth motorhome was like a well-designed, comfortable studio flat on wheels.

Planning your trip

It's a good idea to strike a balance between total freedom and a little forward planning for a road trip like this, says Jeremiah Mahadevan of Practical Motorhome magazine: "The whole point is to explore, but I normally plan a rough route using Google maps and then book the first two or three nights, or at least the first night." However, he adds: "If you are travelling during the summer holidays, it can be harder to just turn up at a campsite." So it may be better to book further in advance.

Any long journey with children can be a trial, and the key to success is in the planning. Try to organise your trip with a maximum journey time per day and drive when the children are likely to nod off.

To buy or to rent?

Buying a campervan or motorhome comes with the obvious inconvenience of having to store and maintain it and you have to use it enough for it to be worth its keep. Prices for small, second-hand two-berth campervans start in the low thousands, but while you may be lucky enough to find a bargain, a lot of vans in this price bracket may be in less than sparkling condition. Motorhomes with four or more berths can cost over £30,000, a huge investment if you only manage the odd long weekend in it. If you haven't yet racked up a huge amount of experience roaming the land in motorhomes, renting a few times before you buy is probably a wise idea.

What does it cost?

Motorhomes are not dirt cheap to rent, but they offer good value for money compared with staying in hotels and eating out, or renting self-catering accommodation and hiring a car. They give you a huge amount of flexibility to explore, and offer more protection from the elements than camping under canvas. Our trip cost around £500 a week, and we worked out that renting several self-catering properties plus a family car, would have cost far more.

Rental costs vary hugely depending on the country, the size and style of the vehicle, the duration of your trip and the season. Roughly speaking, in the UK you can expect to pay around £60 to £80 a night for a two-berth campervan, while a six-berth six may cost at least than £100 a night. You will need to factor in the cost of campsites, too, which start at around £15 but can be more than £30 in popular locations, unless you plan on parking for free. If you can travel outside the peak season in July and August and avoid bank holidays, you can save a considerable amount on rental costs, as well as avoid the worst of the traffic. You may also find a cheaper deal through a broker, such as worldwide-motorhome-hire.com, where you can book motorhomes all over the world.

Check for extra fees, such as charges for bedding or kitchen equipment. Beware, too, of limited mileage or kilometre packages. If you pay for a set amount of miles up front, you could find yourself seriously stung – as we were - when you have to pay a fee for any surplus distance travelled. Go for unlimited mileage deals if you think you will be covering a large distance.

Travelling in Europe

If you plan to travel in mainland Europe, the best option is to rent a van on the continent. Rental costs tend to be lower on the other side of the Channel, as are ferry prices if you drive a standard car over. You will also have the benefit of a left-hand drive vehicle, handy when overtaking slow-moving tractors in the French countryside. Leslie Brown, managing director of campervan rental broker worldwide-motorhome-hire.com, says Germany is the cheapest place to rent a vehicle, but if you are planning a trip to southern Spain and don't have time to trek down from Munich then it will be better to rent in your destination.

Travelling in North America

It's a good idea to compare fly-drive packages against the cost of paying for flights and rental separately. As an idea, basic rental for a standard C25 motorhome, which sleeps five, collected from San Francisco, costs around £380 a week through Cruise America, although that price does not include mileage, which you can buy in chunks of 700 for £135, or extras such as kitchen kits and bedding, which come at a small charge per person. Some rental firms, such as Cruise America, will let you drive over the border to Canada, but some will not. Many have restrictions on crossing into Mexico as well as some major cities, and will not allow travel in the sweltering heat of Death Valley during the summer. Check for any restrictions before you head off.

Travelling with children

If your children need child seats, choose your vehicle carefully. Some companies rent car seats, but many expect you to bring your own.

Make sure to find a campervan with enough three-point harnesses for the car seats. Many motorhomes and campervans only have lap seat belts for passengers, and few car seats can be fitted using these. Even if yours can, you may not be happy with the fit. Many newer vehicles use the Isofix system so any Isofix car seat should fit. This is called LUAS in Canada and LATCH in the US.

Bring plenty of entertainment - story CDs, music they like, well-stocked MP3 players, magazines or car games and a portable DVD player. Even if you don't use them on the journey, these can be useful if you are faced with a rainy evening in the van with the children in a remote campsite.

Free camping

Check the law in the country you are visiting to see if you would be breaking the law by parking overnight for free. Wild camping, as it is known, is not legal in England and Wales, but it is allowed in Scotland. It's also allowed in some European countries, but not all. "Find out about the laws in the country you are planning to visit," advises Mahadevan. "If you decide on wild camping, try not to block other people's views and think about safety issues. You might find you have problems with local trouble makers if you choose a spot in the wrong area."

One great, free, option is a scheme called France Passion, which brings together a network of some 6,000 French farms and vineyards whose owners will let you camp on their land for free for holders of the guidebook, which is available from the website (www.france-passion.com).

The small print

Many campervans and smaller motorhomes are light enough to be covered by standard driving licences, but it is still best to check you are legally able to drive the vehicle. Ethnee Iles of Motorhome Germany warns: "European laws are very strict about this - if a vehicle weighs 3,495kg and the driver's licence is for 3,000 kilos, the vehicle will not be released on day of pick up."

Useful websites

See the motorhomeinfo.co.uk and Practical Motorhome for general tips and advice.

Contact the Camping and Caravanning Club for information and deals on booking campsites across the UK and worldwide.

For rentals in the UK and New Zealand, see justgo.uk.com; worldwide-motorhome-hire.com, brokers deals all over the world.