The questions you are asking here are all good questions to ask any of the surgeons you meet at initial consultation. But to give you more information, here are my unprofessional answers:
*After surgery, you can normally expect to feel able to do normal activity after around six weeks.
*Scaring depends on a number of factors, it's mainly down to how well you heal as everyone is different. On the whole, most peoples scars become unnoticeable after a year or so. Most surgeons cut around the areola. Mr Levick creates a stab wound near the crease in your armpit. This is where he carried out his work on me. You can see the scar if its pointed out, but it's not noticeable and is fading all the time. Scar tissue is negatively impacted by smoking and can delay the healing process as well as leave them more red in colour.
*How you will look after surgery only god can tell you. All the greatest surgeon can tell you is to expect to look closer to normal. Sift through all the before and after photos on this forum to help give you a better idea. Again, you are best to ask your surgeon what are realistic expectations. I'd also advise you put some photos of you chest on this forum as I find other guys opinions quite useful.
*How long will it before you look good? I'm not too sure what you mean by that. As a general rule, you are expected to wait up to a year for a 'final' result, although you will probably find that more than 90% of change occurs in the first six months.
*Side effects? I think you probably mean possible problems post-surgery. Sometimes, unevenness across each pectoral area, but this usually settles over time. Sometimes one side may not look symmetrical to the other and more work may be needed to balance things out. This question is certainly best answered by your surgeon.
Hope that helps.