There are many seed starters you can buy at local garden centers and nurseries. You can even save money and be a little eco-conscious by making your own biodegradable seed starting pots. Then there's a whole world of possibilities in things you can upcycle into seed starter pots like a ghetto greenhouse made from plastic soda bottles, and this seed starter from an ice cube tray.
A little backstory: I came across this idea one day when I wanted to buy seed seed starting trays with individual cells for multiple starts. Instead of buying the seed starters to make I came up with the seed starter ice cube tray. The idea is similar to starting seeds in cardboard egg cartons, but this seed starter can be reused and can last you for a couple of years.
For most of my gardening life I thought that gardening happened in April and May when you sow your seeds and plant your summer vegetable crops and then you spend the rest of summer battling weeds. But as I've encountered more serious vegetable gardeners I've been doing more second season planting in the garden. Whether you call it second season sowing or succession planting, you should plant a second crop of vegetables in summer. Yes, there are seeds to sow in summer for a fall harvest.
Often called the "gateway drug" into gardening, there are few plants that pull someone into gardening like tomatoes do. In Chicago, I've noticed that people who would never call themselves gardeners always seem to make room for one or two tomato plants in their yards, decks, porches and patios. The trick with growing tomatoes here is knowing when to plant tomatoes in Chicago.