Tomatoes are a must for any garden food grower. They are so easy to do and the rewards well outweigh the effort.
I start mine off in little pots with compost. I use seeds from a supermarket tomato. I can highly recommend Marks and Spencers' Italian cherry variety.
Drop on the top of a pot and when they sprout pull out excess seedlings - keeping only the strongest in a single pot.
I keep the pots inside as they sprout and when the roots fill the pot, I pot up into bigger pots - again and again with them eventually getting large pots.
As the frosts fade away - normally in May - I slowly introduce them to the outdoors. A few hours at a time and then eventually all day and finally all night. Now I have a greenhouse, I may add an extra stage and transfer them to a greenhouse before they find their home outside against a sunny wall.
Water well and when they start producing flowers, feed with liquid tomato feed.
Pinch out side shoots and give them a good support - maybe tie up against a trellis and use bamboo canes.
Spend the rest of the summer eating them daily until they inevitably come down with a bit of blight. You can even keep this at bay by cutting off brown and yellow leaves and burning them.
Bliss - so what are you waiting for? Get spreading those seeds.