I used to look after my landlord's 4 rental properties, all in the same street and I had a bedroom in one of the houses.
Be very very careful about who you chose especially if you will be using the same facilities at the same time such as kitchen, bathroom, washing facilities....
Putting rules in place beforehand will mean you both know where you stand and prevents problems from coming up at a later date.
How big is the bedroom? Could it incorporate a TV and maybe a comfy chair or sofa so they have their own space?
If they are to help with cleaning then a rota would be best, you would also need to decide what to do about food, cooking equipment, buying of cleaning products including things like washing up liquid and things like toilet rolls.
I would suggest a trial period if that would be acceptable to them to see how you get on living together.
Don't be too lax on rent payment or if other issues come up, some things can't be helped but it can be a slippery slope.
Think about what you would want to do about pets or visitors, especially any overnight visitors and partners.
Not just in the sense of them being there but if they become a regular like a partner then what about utilities etc...
It may be easier to have one weekly or monthly payments on direct debit which include a contribution to council tax, utilities etc... rather than trying to split bills.
Make sure you know any tax implications relating to the extra money.
Make sure you get a proper agreement in place but make sure you are aware of the tenant's rights as well as your own.
Sit down and brainstorm possible things to think about like cutting keys and making sure other people don't get access to the property (eg make it a breach of tenancy agreement to give keys to others).