Questions about subletting a room as a tenant

[zya19]

Hi everyone,

We're a family of expats renting a whole condo unit. Recently we got into an agreement with the landlord that we can sublet a room to a secondary tenant we find. There are a few things I want to check before we make up my mind and learn how subletting works (there seems to be surprisingly little information about tenant's subletting online, only landlords' subletting... if there's any online documentation about this, I'd be happy to be pointed in the direction).

1. Is anything other than the landlord's consent required before we're legally allowed to sublet a room? I'm aware I need to check things about the sub-tenant like whether they have a student or a work pass.
2. How does the paperwork between us, the owner and the sub-tenant work? I'm assuming the sub-tenant signs an agreement with us, does the owner need to be involved in the paperwork as well? Are we required to share the tenancy agreement between us and the landlord with the sub-tenant?
3. Does the rent paid by the sub-tenant to us count as our income to be taxed? Or is it just a case of shared rent? Does it depend on any factor (how much the rent for us and the sub-tenant is, who decides the rent, etc)?
4. Any other advice is much appreciated.

Thanks in advice.