Easy really, especially if you live close to the property.
- You can get contracts on-line, I get mine from the local university's accommodation office site. Your tenants will have an exsiting contract though, can you adopt that?
- You must use a deposit protection scheme. Just look them up, it's quite straightforward.
- Sounds like you're dealing woth the practical stuff anyway so you'll know about gas safety certs, responding quickly to problems etc.
I do everything myself now with a rented house locally and also did so far many years with another house, while living some hours away and going there once a year to see new tenants, do contracts etc. If things needed fixing, I rang the appropriate person, co-ordinated with the tenants and got it sorted out. Not recommending distance landlording, there is potential for things to go wrong in that scenario but I was in a landlord's market, so could be choosy and generally got capable tenants I could trust.
As a tenant at the same time, often dealing with agents, I concluded that they are universally rubbish and take money for doing nothing. All questions or problems were just passed on to the landlord, the agent took no action. Then they'd expect me to be in on a weekday to let people in to fix things, despite advertising for people in work only. It makes me spitty thinking about it, I'd never employ one to deal with my house.
If you find you need to get new tenants, always check references - not just form the current landlord who may have a vested interest in getting rid of them, meet them face to face and go with gut feeling about whether or not they are essentially 'ok'.