Aloha,
Why would you need to be there to let in contractors? If a Tenant requests a repair, we provide the Tenant contact info to the Vendor, who then coordinates direct with Tenant. The Vendor, depending on the task, is required to call me from site and/or send pics from site to discuss and authorize their proposed repair.
Be very careful you do not end up with either squatters or a stripped out unit.
Does local law require you to "post a notice"? If not, simply mail, Certified, Return Receipt Requested. Save any returned, unopened items as well as the signature card when you get it back. Some Tenants will never "accept" Certified mail, so you also send by Regular Mail if local law considers that "proper notice".
As long as you know what you are looking at, you absolutely should get "eyes on" when "Rent Ready", and annually. Prevention of problems is far less costly than remediation. Providing neighboring Owners (make sure they are not someone else's Tenants!) your contact info and introducing yourself can go a long way toward preserving your property.
If you are not very familiar with local LL/Tenant laws, including SD limits and handling, State and Federal Fair Housing Laws, Fair Credit Reporting Act, Service Members Civil Relief Act, HUD and EPA regulations, local contractor licensing requirements, and the States definition of "Real Estate Activities"; OR, if you are generally unfamiliar with residential construction and inexperienced at leak detection, and household systems troubleshooting, you should probably hire a qualified PM.