It's a fairly simple dish to make, don't worry. Start by making a basic bolognese sauce - this can be used for spag bol too.
Melt 1 tablespoon of oil and knob of butter in a pan.. Add a chopped onion, 2 chopped celery sticks, a chopped carrot, 4oz mushrooms and a crushed garlic clove. Add about 1lb of minced beef and cook until brown. Then add 12 oz (350ml) of stock (a stock cube and water), 2 tablespoons of tomato puree and a bay leaf and bring the whole lot to the boil. Cover and cook for 45 mins on a low heat, stirring occasionally.
Next make the sauce by putting 1oz of flour, 1oz of butter and 3/4 of milk in a pan, heat and which until suace thickens, boils and is smooth. Cook for a minute. Remove from hear and add a pinch of ground nutmeg, 1/2 teaspoon of mustard and about 2oz of grated cheese. Take a rectangular ovenproof dish and place some of the bolognese sauce at the bottom, then cover with about four ready-cooked lasagne sheets. (don't soak these) Cover with more meaty sauce and repeat the layers. Pout the cheese sauce over the final layer and sprinkle a bit more grated cheese on top. Bake at 180c (35)f) Mark 6 for 35 minutes until golden and pasta is tender.