Road tax is usually done by the leasing company (as they hold the V5).
Lots of new cars come with some sort of breakdown cover included so it may have it, may not.
Insurance – no.
Servicing/tyres – no, unless it's a "maintained" contract.
Usually you pay a lease to use it, and also all the costs
IMO only sensible on cheap new cars, where you intend to replace with a new lease every 3/4 years.
If you do get one, go with the lowest mileage (keeps the monthly cost down) and when you have to give it back its a simple calculation – is it cheaper to pay the fine, or buy the car and then sell it later.
If by lease, you mean Contract Hire then all you normally get is a car and some tax every year.
Unless you do mega mileage don't bother with a maintenance contract as most new cars have service intervals of up to 20,000 miles so the extra you pay every month adds up to more than the one service you need in a 3 year contract.
b r is right about mileage, so long as the excess mileage charge isn't stupid (sub 10ppm) pay the adjustment at the end. If you end overestimate your mileage, however, you get nothing back and the lease company profits when they auction the car off.