How Does Equity Research Recruitment Work?

Just as the title says, how does recruitment typically work?
Specifically:
- Are new associates hired every year across all coverage groups?
- Do you get to pick your coverage group when starting out?
- Is there a time when all banks/independents are hiring new grads? Or is hiring done on an as-needed basis?
- Are there any independent shops in Canada that you would recommend over others? Would you recommend any of these over bank's research teams? (Not much info available on Canada)

Any info is appreciated, thanks!