The EMHC, priest or deacon will contact you if it is a home visit. Anything they may need special they should tell you on the phone, but usually there is nothing special required.
If you are homebound for non-dietary reasons it would be a good idea not to eat for an hour before receiving but for medical reasons the 1 hour fast can be waived. Also it would be a good idea to turn off any TVs or radios right before they get there. If you want you can pray a little to yourself, watch EWTN, etc. to “put yourself in the mood.”
If you are hospital bound the 1 hour fast doesn’t necessarily apply due to the fact that the “rounds” may not correspond well with meal times and your illness may not allow fasting.
The person will have the entire rite with them, nothing special is required from you other then normal answer and prayers that you should already know (i.e. the Lord’s Prayer.)
You should contact the local parish or your parish to arrange for this. Some hospitals will assign people to visit you if you ask for it on your admission forms, but don’t assume that especially if in a non-Catholic hospital.