1) I suggest using Multibit, download it. Make sure you backup your wallet in a safe place.
2) I don't suggest mining, unless you are trying to invest into a REALLY nice rig. Just accept sales via BTC (that's just what I do)
3) Don't waste your time if you have a laptop, or have a regular computer, you'll need to customize a specific PC too get some good rates going.
I recommend googling "Blockchain" to learn about setting up a wallet.
I believe it's worth to do whatever you want. Personally, I just use it because it's a good currency for online transactions and I enjoy being in complete control of my money. Mining depends completely on your computer and may not be worth it at all if you're on a laptop. http://www.reddit.com/r/Bitcoin/comments/18r5qc/will_i_earn_money_by_mining_an_answer_to_all/ This thread should help you out a lot.
Shoot me a message if you need any help.