Hello I'm new to frequent flying but will be traveling monthly from Dublin Ireland to Detroit for the next 16 Months (Economy). I have already flown this route a couple of times last year.

I have three route options.
1.DUB-NEWARK-DTW with Continental
2.DUB-AMSTERDAM-DTW with KLM
3.DUB-LHR-DTW with BA

I probably will not always be flying the same route - depends on price

Im a member of Continental (Elite) and KLM

Some questions

What is the best FF club to join, or do I join them all so when I fly each Airline I rack up points

Do I just keep with Continental and claim the flights on KLM into my Continental account

Can you have two cards and when you fly continental claim these with Continental but also with their partner KLM

As you can see I'm confused with what is going on in th industry, really I'm trying to maximise the No. of points so I can get a few free flights or upgrades.

All help appreciated.