pulling the plugs and pumping the oil out is something ive never thought about doing, but is probly good advice.
when i flipped my 95 jeep wrangler (4.0L six), it sat upside down for quite a while before the tow truck showed up. once flipped i just let it sit for a good bit. and fired it up. you just have to accept that youre gonna be spraying for mesquitos for a while. (burned oil), obviously be sure to check all your fluid levels, tranny, oil, water, to make sure all is good to go.
have to say, that experience is the reason i bought my M1009. that jeep flipped three times driving through the snow, down a street, at 25-35 mph. although i will attest that the roll bar did its job and both my friend and i walked away with only bruises. even though she was thrown 30 feet from the car the first time it went over. no lie..... she was wearing a superman tshirt.