You will be growing Basil in no time with some simple advice. Basil growing will provide you with Pesto in abundance. Then enjoy it together with the tomatoes that you grew earlier.
Basil and Tomatoes like growing together and also prefer to be eaten together. Simple.
Let some Basil self seed and take care of themselves. But be aware that different varieties cross breed. You may be pleasantly surprised. Or maybe not.
Last time I looked the seed catalogue was bursting with all kinds of Basil varieties. Apart from the regular Sweet Basil, you can buy Thai Basil, Greek Basil, Perennial Basil, Lemon Basil...but some of those are different species of Ocimum.
Starting: The seeds germinate in about a week. In cooler climates it's best to start seedlings indoors for planting out in a warm sunny spot in summer. Space them 30 cm apart.
Soil: Well drained compost or rich loam is best for planting Basil.
Climate: Hot and sunny is definetly preferred. Do not expose to frost.
Watering: The Basil plant needs regular watering, but be careful not to overwater.
Fertilizing: Feed fornightly to produce a better tasting plant.
Harvesting: Harvest tops from about 3-4 weeks to promote bushy growth. Remove flower stalks. The leaves on Basil are tender and soft while the plant is small, but as they mature they will become rougher.
Containers: Basil plants are perfect to grow in containers. A depth of 10 cm is enough.
Shady areas: It's difficult to grow Basil in shade. Sweet Basil will never be very vigorous, but Perennial Basil or Greek Basil manage better.
Indoors: In winter you can have some Basil growing on a warm windowsill. Use the plants while they're still young.