I assume landscaping but what about changing out a/c filters or other maintenance?

Your time here will be well spent.Now that you have made the move, below are some links that will help with the navigation of the site. http://www.biggerpockets.com/startherehttp://www.biggerpockets.com/meethttps://www.biggerpockets.com/alertsHow to Use @Mentions on BiggerPocketshttps://www.biggerpockets.com/ruleshttps://www.biggerpockets.com/inviteshttps://www.biggerpockets.com/forums/categorieshttps://www.udemy.com/biggerpockets-real-estate-investing-course/ (video with 64 lectures and approx 6hrs of material)https://www.biggerpockets.com/real-estate-investing (Ultimate beginner's guide to REI)Before your 1st purchase, please ensure you visit the below link for some tips.https://www.biggerpockets.com/renewsblog/2014/12/19/real-estate-investing-success-smart-tips/REI books suggested by BPershttps://www.biggerpockets.com/renewsblog/2015/11/13/7-real-estate-books-beginner-investors/ (7 absolute must read books for beginner REIs)http://www.biggerpockets.com/renewsblog/2013/04/14/best-real-estate-books/?

If so, does anyone have any tips to help us to maximize cash flow?

Please feel free to reach out, I'd be glad to share information on the landscape with you!

I'm afraid you have seen only the tip of the iceberg regarding damages, especially since the place is full of their stuff.Not addressing issues as they arise, not serving appropriate notices for lease violations in a timely manner, not charging for damages as you discover them..... you are in a world of hurt.... and I feel for you.

I am just inquiring for any helpful tips, hints, and knowledge to get started.  

Ok, now that you have taken your initial step, below are some quick links to get engaged.Since you didn't mention an area of interest, I added links below to three of the most popular niches for you to choose one or all.http://www.biggerpockets.com/renewsblog/2013/02/22/buying-rental-property/ (how to buy a rental property) http://www.biggerpockets.com/renewsblog/2014/01/07/flipping-houses/ (step by step guide to flips)https://www.biggerpockets.com/renewsblog/2015/01/31/ultimate-beginners-guide-real-estate-wholesaling-2/ (Ultimate beginners guide to wholesaling) http://www.biggerpockets.com/startherehttp://www.biggerpockets.com/meethttps://www.biggerpockets.com/alertsHow to Use @Mentions on BiggerPocketshttps://www.biggerpockets.com/ruleshttps://www.biggerpockets.com/inviteshttps://www.biggerpockets.com/forums/categorieshttps://www.udemy.com/biggerpockets-real-estate-investing-course/ (video with 64 lectures and approx 6hrs of material)https://www.biggerpockets.com/real-estate-investing (Ultimate beginner's guide to REI)REI can be very daunting, but, before you go searching for that 1st buy, please take a few minutes to bone up on the tips in link below.https://www.biggerpockets.com/renewsblog/2014/12/19/real-estate-investing-success-smart-tips/REI books suggested by BPershttps://www.biggerpockets.com/renewsblog/2015/11/13/7-real-estate-books-beginner-investors/ (7 absolute must read books for beginner REI)http://www.biggerpockets.com/renewsblog/2013/04/14/best-real-estate-books/?

A variation on the theme which I considered but chose not to use would be, instead of buying the appliances, window coverings, bathroom finishings and landscaping, I could have given the tenants an “upgrade” budget, where I still approve and pay for stuff, but they pick it out and choose the installers and landscapers and painters.

Hello all, I'm a new investor looking into multifamily houses, Any advice, tips or suggestions.

Amy tips is welcomed .