I bought an investment property in 2006 for $103.5k and rented the property with a cash flow of ~$175/month until the summer of 2015 when a particularly problematic tenant finally left.

During the summer of 2015 I made the decision to leave my teaching job and focus solely on my sister and I's restaurant as well as I started expanding my own real estate business.

Rather straight forward, Give proper notice you will be increasing rent, do it for all the units.Keep them all on month to month.Don't worry if they have big mouths, the next tenants could have big mouths also, but you could mention that you would appreciate  it and that you would want them to be polite to any new people on the property, you are aware of what they mentioned during the tour you took, and if they have plans on moving you'd be happy to work with them as your impression is they aren't as satisfied as they could be living there.Wait till late spring, early summer if you plan on doing a non-renewal notice.. that gives them time for proper notice if they are going to decide to move and some time to adjust to you as new owner.

San Fernando Valley gets very hot during the summer and then relatively cold during winter and even some summer nights.

I'm a Military member and have to rent my house out this summer.

@Becca Summers I have to giggle at the probably unintentional "swear equity" seeing as that is often what it turns into.  

Many landlords set up leases to end during the summer months as that is when demand tends to be higher for rentals.

Only a few places like Celebration seem to be worth it.

This doesn't speak to investing in multifamily vs sfh, but I can share my experience/evolution in rei since starting this past summer.

My father passed away this summer, and left 2 rentals for my mom.