Question
James,
This question is really a two-parter. Moved into a new hoem recently, and am encountering some areas that are relatively new to me.  

I understand the basics of mulch.  We were offered hardwood chips ($4 for 3 cu ft): Is this a good type of mulch?  Will mulch help to stop poison ivy from growing on slight incline (concern is that water may cause mulch to run off)?

The back of our house has a hill that slopes away.  Although no one has expressed concern about erosion issues, I'm a little worried.  That is, there's hardly any grass and it's mostly dirt.  This is a very broad question, but what are some telltale signs of potential erosion issues?  Is there a specific type of expert I should seek to take a look?  Landscapers aren't really the best at spotting this potential issue unless it's clearly evident.

Any general info would be appreciated; I need an objective straightforward answer, which is something that landscapers/lawn folks can't provide (since they're trying to entice us to use them).

Thanks.

Answer
Hi Len, If the soil is loose fill from grading at construction, then there is a real potential for erosion which you should have seen at the first rain.  If it's natural, the potential is there, it will be much slower, and the rate of erosion will depend largely on how much runoff will occur because of the house.  Will a dry creek take the runoff down the hill more efficiently?
Mulch may be an option for covering the slope, however wood chips tend to float, so I'd prefer shredded mulch or pine needles.  If the slope is very steep, then even these may wash.
Turf or groundcovers are a better option for holding the soil.  
If the soil is loose, I'd cover the area with landscape fabric which will immediately stop the erosion.  Then, either cover with mulch or plant groundcovers through the fabric and let them root through it and cover the area.
This gives you the quickest results and it will stop your poison ivy from coming up because the seed can't get to the ground.  Without the landscape fabric, mulch alone will encourage your poison ivy to come up from seed.
You said there is hardly any grass. Why?  Is is shaded?  If so, then focus on ground covers or let it return to the woodland it once was.  If it's sunny, then work on the health of the grass.  
If it's "mostly dirt", ask yourself why. Are you trying to grow a pasture in the woods?  It's a lot easier to with nature, than against it.  Jim