Not sure if I'm on the correct website (UK based), let alone forum, but I'll give it a go anyway.

I will be booking several long haul flights in the upcoming motnhs, and want to make the most of them.

Basically, I want to start collecting airmiles/points/whatever they're called, but have no idea where to start.

I made a return trip from LHR - SFO for which I have retained the boarding pass.

I have recently received a BA Executive Club Card for which I am hoping to transfer these miles, and have another return flight booked from LHR - SFO in a couple of weeks.

Some of the things I need to know:

1. What am I potentially gaining from this card.
2. If I book flights for other people, can I receive the points/miles (what's the differencr?).
3. I don't (and never have), owned a credit card. Is it worth getting one to give me more points - I have seen a couple of BA ones.
4. I am booking a return flight from someone from SFO - LHR, who has also ordered a BA club card. Virgin fly at about $30 cheaper than BA, and she likes flying Virgin. Is it worth the value of paying an extra $30 and her flying BA for what she will get in points/miles...and what the hell can they be used for anyway?

Sorry for the vagueness, I really have no idea what I'm doing, or what I can get.

If someone can advise what the best course of action is to make the most out of flying it would be appreciated.

Thanks in advance.