Tweety, I use Steve's Chicken Tracker that can be found here:
https://www.backyardchickens.com/t/...or-tracking-expenses-and-income-from-chickens to track my income and expenses. It is already VERY well set up for a backyard flock, if all you are interested in is keeping track of how much your hobby
makes costs you. There is a tab for each month of the year, plus a tab for the total. The figures you enter by month automatically transfer over to the summary tab so you can see at a glance how much you have spent all year, and how much you have made in egg sales. You can track eggs collected by color, number of laying hens, eggs sold (by dozen), as well as feed & supplies purchased, and any flock purchases or hatching eggs sold. It really is very well thought out.
I've used it ever since I started. One year I actually tendered a $3/month PROFIT!!! Actually, that number isn't exactly right because the one thing it doesn't track all that well is the number of eggs you eat. In other words, it tells you how many you collect and how many you sell but not the number left over. Any egg I collected but didn't sell was eaten by my family, which means that in addition to the $3 per month income, we had FREE eggs. Yeah!!!
Unfortunately, that was when I was trying to be practical and the chooks had to pay for themselves. Since then it has become more of a hobby and I, ahem, now run at a loss every year.
For example, the first year I acquired barnyard mutts from a local gal for a very low price. Last year I bought expensive hatching eggs and incubated them. Believe it or not, that made a difference.