If it's an asphalt shingle roof, there's a whole lot less to imagine than you would imagine.

I've listed below the order I plan to attack things in, let me know if this sequence makes sense:Resolve excess moisture under house (minor grading issue, gutter required, possible plumbing leak)Repair minor roof leaks (repair flashing, seal leaks around chimney, replace tree-damaged shingles)Trim trees away from houseInstall 50 concrete piers and level foundation (foundation had work done previously but shifter due to excess moisture)Install vapor barrierAdd structural roof support beams in attic, add insulationRepair rotten siding/soffit/window frames (mostly upstairs)Repair porch (replace rotten boards, sand & paint)Paint exteriorInstall central AC/Mini-split system (any recommendations on this?)

Single family ranch, 3/4 acre lot, septic, 8 year old 3 tab shingle roofPurchased: 2006 for $140kOwe: $100kMortgage: $543Taxes and Insurance: $205Expected rent: $1200-$1350Tenant would cover utilitiesThere are no association feesI will have a property managerI am guessing 3-5 years before predictable large capital expenses arise.  

@Justin GreenI have a house with asbestos shingles and they are a 100 year product. 

@Christine Swaidan How old is the roof and is there visible signs of wear such as curling, missing shingles, ect?

I guarantee you that many ripped and torn off shingles will be found in his snow pile and he will have roof issues as well.

I would go architectural shingles as it is a much better product, for a moderate price increase.

Newly shingled roofs and all duplexes are located in their own sub-division.  

To further emphasize my point, here is an illustration ... say there is a 1550 SF house in Los Angeles, composite shingle roof, stucco exterior, etc.

Things I think we should look for are asbestos, lead base paint, floor settling and sinking, shingles popping up, closet space/fire place, galvanized plumbing.