Where to connect the jumper for starting car with bad battery?

If it was me, I'd connect the red, or positive, cable directly to the positive post (marked with a + sign) OF THE BAD BATTERY FIRST. This will hopefully prevent igniting explosive gases around the post.of the defective battery. Then find a good, paint-free ground position on the engine block to clamp the black, or negative, cable. This will by- pass the bad battery completely. Follow the same order when connecting the battery cables to the good battery, red clamp on the positive (+) post, and the black cable onto a good connection on the engine block. You will probably see a small spark when making this connection - do not worry, this means you've correctly connected everything. IF YOU CAUSE A LARGE SPARK, OR ARC, you have crossed the connections. Disconnect everything and try again. The batteries are filled with a diluted mixture of SULFURIC ACID and should be handled with EXTREME CAUTION. You should wear protective glasses and rubber gloves. The acid and could cause severe skin injury and the loss of your sight if any of a numbers of things happen. GOOD LUCK!