Get some peat pots and your seeds and sow some of each you want to grow. Dont sow alot unless you want alot. Then get the book gardening for dummies and follow its advice for watering and hardening off. Every month repeat and you can have a continual harvest. You need to skip months 90 days before you cant plant outside due to weather and start again 90 days before your last frost.Or so. I plant in containers and have adopted a gardening philosophy from years of reading online, books, talking to people. The core sum of all my knowledge is plant what you like or would like, research those items and have fun!

Here is a link that might be useful: robs urban farm

Wow, you are lucky to live in Iowa, your University Extension Office has a nice selection of free publications for the home gardener. Here are a few links to get you started. i'm thinking you might need to buy some of the plants you want to harvest as transplants this year and start from seed a little earlier next year but i am far from your zone. i'm sure someone closer will be able to give you better advice. Try adding your zone to your profile if you can. Good Luck ; )

How to plan a vegetable garden by Iowa State University

Planting and harvesting times by Iowa State

First and Last Frost Dates for Iowa State

We garden in Madison, Wisconsin. We have similar weather, and similar soil. We always use tomato seedlings, from the local farmers market. We also use broccoli and brussels sprouts seedlings. Swiss chard is planted from seed, and does very well here. Cherry tomatoes are easier to grow than full-size tomatoes-they are very prolific, and they seem to be more resistant to various tomato plant diseases.