Use the template found here:
[b]Staff Member(s) Name:[/b]
[b]Staff Member(s) SteamID:[/b]
[b]What Did The Staff Member(s) do?:[/b]
[b]What Server(s) Was This On?:[/b]
[b]Evidence:[/b]
Additionally, evidence would usually be required for such claims, as they're not things that the staff member in question is likely to admit to.
A good recording software is PlaysTV:
Click here to download PlaysTV.
This will not ruin your chances of applying for staff, as you can apply with the recent punishment and you will still be considered, just with a lower chance of getting accepted. Additionally, 2 weeks after the punishment is placed, it will no longer be considered when you apply for staff.