Jack up barn, insert concrete footings

Hi everyone. I bought an old house and property 3 years ago and have been renovating it ever since. There is a 100yr old barn on the property that is sinking into the groung in places due to the cedar posts sitting on the dirt.

I need to jack up the barn and place concrete footings under each post. Does anyone have any good advice for this? ie. what kind of jacks, how deep to dig the holes, how big to make the concrete blocks, how tall to make the sona tubes ... etc. Is there an online tutorial for such a thing?

Here are some pictures of my barn and the posts:

Hi Josh -
There's a guy here in the Koots that is known as the 'house lifter', and I'm sure he would be able to give you some great advice. If you send me your email I can give you his name and #.
I don't know if he has internet, but I can print out the pics for him if he needs.
*Kristina

Hi I've lifted up anything from bridges to houses and usually goes like this. I use Hydrolic jacks to do the lifting and go to screw jacks or adjustable tube jacks to take up the slack... In other words Lift up S L O W L E Y about a 1/2 to an inch at a time and use the cheaper jacks to take up the slack and hold everything in place.. Going an inch or less a day....any cracking stop and hold everything in place and check out what it was. usually nothing but it could be a tenon or some bad thing letting loose .... And go on after holding everything in place... They now make those plastic things post hole bottoms that hold 20'000 lbs and up that have to be dug in below the frost line and I've heard some good reports on them...although I've dug out 4 X 4 foot holes in very wet land and filled and vibrated rock 3/4 to 1 1/2 inch and poured a 12 reinforced pad on top to hold the weight and keep any winter frost change anything......best of luck in the future..RMD