help with tomatoes please.

Hello

 my son has given me some tomatoes to grow they are about 8 inches tall and i have just put them in larger pots. I remeber when my mum used to grow them she used to 'pinch out' the leaves but i cant remember why or how does anyone else do this if so why and how do you do it please.

You might find this link helpful - info plus video...

http://www.rhs.org.uk/Gardening/Grow-Your-Own/Veg-A-to-Z/Tomatoes

When they grow larger, they will produce sideshoots at the point where each main leaf joins the main stem.  These will make the plants grow bushy and although there may be more fruit, there may not be time for it to ripen, so most tomato growers pinch out these sideshoots as soon as they are seen.  This is known as the 'cordon' growing method.  Whatever you do, don't remove shoots that come from the main stem where there isn't a leaf as these are the flowers!  Only remove sideshoots for 'cordon' varieties though.  With 'bush' types, you need do nothing.  Ask your son what variety they are and we can tell you whether to pinch them out or not.

Here's a YouTube video showing how to do it:

http://www.youtube.com/watch?v=EtFnORJBQ90

Another reason to pinch out sideshoots is to free up some room for air to circulate. A mass of foliage and no air circulation are ideal conditions for fungal problems.

does the advice about pinching out side shoots hold for cherry tomatoes too?  

Depends if they're determinate (the bush type, the ones that don't grow beyond the fruit) or indeterminate (the ones that keep growing while fruiting). You don't need to pinch out the determinate varieties.