What is the best method for adding Calcium to a "about to be tilled"

The garden should be tilled first,then add granular limestone based on your square footage.

Yes till first.

Save your egg shells - crush them (easy to do with your hand or a rolling pin) scatter them around your freshly planted tomatoes & peppers.

Use Bone Meal, available at almost any garden center. Just follow the directions on the box.

Well, I use skim milk powder available at the bulk barn, and combine with Epsom Salts..I add to each planting hole as I plant...ration is 2 salts to 1 calcium...if seeding..same deal....add to seeding trough ... many use the 1 to 1 ratio...but soil already contains calcium all by itself...but it no longer contains magnesium unless your property is spring fed through limestone beds....the skim milk powder is the highest grade of calcium...breaks down immediately...for availability during the growing season of the annual vegetable crop...you want a laugh??..I also plopped in a calcium pill that I used to take...and when harvest time came most of those were still in the root ball, partially dissolved...knowledge by accident often is priceless...Roz

Till the garden, dig holes for tomatoes about 2" shorter than the height of the plants, add one handful of crushed, dried egg shells to bottom of hole, mix with dirt in bottom of hole, take off all leaves except the very top ones from the tomato plants, plant tomatoes deep. mudding in as you fill in with the dirt, sprinkle another generous handful of the egg shells, and stretch out the soaker hoses around the patch. The stems underground will get roots all over them which will help feed the plants and make them sturdies. The egg shells will give calcium to the plants every time they're watered which will, in turn, prevent the dreaded 'blossom-end' rot on the bottom of the tomatoes; the egg shells will also keep away all cutworms, etc. from crawling up to, curling around the plants, and eating them off for their breakfasts. I plant the peppers the same way except they can only be planted as deep as they are in their original pots/packs. After planting the tomato & pepper plants (as well as cukes, squash, melons, etc., I plant marigolds around the entire garden - they prevent all the nasty bugs from getting on my plants. My 76-yr-old hubby and I raise 2 large gardens of veggies and berries every year, always have lots & lots of produce, and never have any problems with bugs, diseases, etc. Have fun!

Crushed egg shells work great and the don't cost anything. Dry them and then crush them. You could save them in a container over the winter and then you would have enough for when you till your garden.