many thanks for the advise. I am outside M25 but not far off, start of Kent. Any specific grass/turf name yo suggest.I don't know where you are based but where I am (inside the M25) a sq mtr of turf is about £3.50. For that you will get good quality general purpose turf suitable for your garden. Don't waste your money on luxury turf containing fine grasses.
General purpose turf will be fine. It will have ryegrass in the mix so that's suitable for kids as it is hard wearing. Examine the turf if you can when it is delivered - it should not contain any weeds and be of good colour, bright green instead of dull. Ideally the soil underneath should be moist and should not break up when you lift it. When delivered the turf should be unrolled if possible and, when installed, watered everyday until roots take. You will know the roots gave taken when you attempt to lift a corner. If difficult it means the roots have found their way to the soil underneath. First cut on high setting after about 10 days. Keep everyone off it for about three weeks. If you need to walk on it for any reason before then use scaffolding boards or similar.
Get yourself a decent sprinkler and The Lawn Expert by DG Hessayon.
Cheers