As an ex Emergency RN the most important thing you can do for anyone is simply give something a go. Even if you arent sure you are doing it 100%, its going to be better than nothing at all.

Dont get too caught up in the 30:2. Its a good guideline but i can assure you that when you are in a real life arrest, counting may be something that may not come to you, or you may get confused about what the correct ration is. Just do compressions and breaths as much as you can manage. And you WILL get tired. Get someone in to assist you and take over from you at regular intervals. A tired person will not effectively give CPR. Don't be afraid to admit that you are tired and need help. Its hard work and very different on a human body.

And spot on about chocking up the side of a pregnant woman. The same can be applied if you happen to come across a pregnant lady who has collapsed etc. Place a pillow or similar under her right hip so that her belly moves to the left, or you can physically pull the belly over to the left.

Great thread with loads of useful info for all. Its never too late to learn basic life support. You never know when you may need to help someone.

Hopefully no one ever needs to use the skills