I've decided to get into single-issues rather than trade waiting, mainly due to impatience. But I have a few questions:

1.Is it wise to stack them like trades on a shelf?
2. What's the best website to buy them, on release day? I have a local hobby store near me of corse, but they only put out new comics every 2-3 weeks.
3. I don't care about collecting everything, but are variants something I should keep notice of?