HMRC have guidance on their website to assist landlords, that now includes a couple of useful webinars, which you can find here: https://www.gov.uk/guidance/help-and-support-for-landlords.
This is however just a general overview and, as there are many aspects of letting businesses which are not clear, we would always suggest getting advice from the outset. Failure to understand the necessary tax obligations can be costly.
Do let us know if you need support or guidance with regards to your rental property.
Disclaimer - All information in this post was correct at time of writing.