We only have 2 rentals right now and my husband and I manage them ourselves.
One tenant is on Section 8, the other on rental assistance, so the rent checks come directly to the PO Box made out to the LLC.
We advertise mostly on craigslist and with signs on the property. My contractor will show the house (I pay him a set amount for unlimited showings, as he lives nearby). I use Excel spreadsheets to track expenses and rental income.
We have a carpenter, electrician, plumber and landscape guy that we call for repairs that we can't do, or don't have time to do, since we live an hour from the properties.
Our tenants call directly with any issues. We document what gets done, take photos, save receipts, and keep good records, including phone calls and correspondence via texts (tenants love texting). Last night a tenant called and said the thermostat wasn't working. My husband asked her right away if she had accidentally turned off the furnace switch. She had. Problem solved in 30 seconds.
We had an eviction in the late summer that our attorney handled - $300 for legal services.
At tax time, I give our accountant the spreadsheet. I have QuickBooks, but only use Quicken for checking accounts. I find the simple Excel spreadsheet works best. No need to over-engineer the process.
Hope this helps!