Hi all, I'm first time poster

looking for some feedback on a couple of issues. I've been mainly playing lowlimit ( $10 + 1 ) SnG's for the last few months.
1) Could people tell me what a good return is for SnG's? And as a related issue, what a 'significant' sample size would be in order to draw conclusions from this.
2)I've played on a couple of online poker sites and was wondering if people would give me their opinions on which ones are best for SnG action and why.
Thanks