The best thing you can do is follow the checklist on the IRCC website for what you need to submit in the sponsorship application package.
However given your situation with OW, I would also include the following: (1) evidence you have stopped taking OW from the province; (2) evidence of your income from all of your jobs, including employment letters and NOA; (2) bank account statement. You can also include evidence of your partner's previous employment and income and have him include an LOE indicating he plans to pursue the same career / employment in Canada once an OWP is granted as part of the inland application.
