If you are new to canning or would like more strawberry, less sugar taste, you might consider using powdered pectin ( sure jell makes one that is designed for less sugar, in the pink box). If not I have had good results with a basic 2 quarts crushed berries and 6 cups sugar....makes about 4 pints. i would add herbs toward the end of cooking. As with anything the longer the herbs cook the more their flavor will diminish. Also, they will continue to cook as they are processed if you hot water bath them. Basil might be an attractive companion, but pure strawberry is always wonderful.

Yes, by all means use the lemon juice. But with berries, the general formula is 3/4 cup of sugar per 2 cups crushed fruit. Sometimes I let the berries and sugar macerate overnight, then make the jam the next day. Some fruits lend themselves to herbs, etc., as additions to jam, but strawberries strike me as an odd candidate. Why would you want to taste anything but strawberry? Rhubarb, finely diced, does, however, make a nice addition.

Take a look at this link; it has some good tips on how to safely can:
http://www.make-stuff.com/cooking/canning_basics.html

For delicate or leafy herbs, I would add them towards the end of the cooking process--probably about 5-10min before it's finished. I usually cook spices with the fruit from the beginning, especially if I use whole spices as a part of the syrup and strain them out later. You'll get better flavor from them the longer they're in the mixture.

1 cup of sugar and 1 tablespoon of lemon juice for each 2 cups of sugar. Process in a boiling water bath for 10 minutes. The lemon juice is important for jelling natural pectins as well as lowering the Ph for safe preservation.