Was gonna type a lot but found this instead lol

Just make sure your timed at TDC marked on the crank pulley on the compression stroke. You can check the compression stroke by looking at the distributor and making sure it's pointed at piston 1 on the distributor cap. If it's pointed at 4. Your not on the compression stroke.

And just make sure your flush / drain out the fluids before hand.

http://www.youtube.com/watch?v=inJK7vf5RBw
http://www.youtube.com/watch?v=t7ckRCzHGS0&feature=related