Some quick IDs -- at least a starting point for you to go look at examples and see if they match or not. Going left to right on the first row, then left to right across second row, and so on...
1 - Vinca? Looks bushier though, so it may be a species of Euonymous
2 - Juniper sp. (probably one of the creeping or prostrate varieities)
3 - Hemlock? or possibly yew?
4 - Laurel? (Actually a Rhododendron sp.)
5 - Juniper sp. again
6 - Very familiar... I will try to remember and let you know if I think of it
7 -Looks familiar but the name escapes me
8 - Lonicera? (honeysuckle) This is a vine, so I don't think it is a rhododendron at any rate, though it may resemble one.
9 - This reminds me of an avocado for some reason, but I am guessing it is merely a frost damaged Lonicera.
10 - This looks like an edible green of some sort with a basal rosette - will have to do more research, but from the state of decay, it is hard to be sure.
11- Geum (probably aleppicum or yellow avens)
12 - Possibly a chrysanthemum sp. -- there are so many, it would be hard to say which from this specimen.
13 - Some sort of deciduous shrub -- can't tell from the photo (could be another hydrangea, I suppose, but there is no tell-tale flower head to make it easy for ID like #19)
14 - some sort of ground cover plant - appears to be a trailing plant with soft stems
15 - No idea, but it looks tropical! (You're in Maine?!)
16 & 18 - Sedums, I am pretty sure. A popular variety is 'Autumn Joy' so that may be what you have.
17 - rhododendron again?
19 - Hydrangea
Some great places to look for plant identifications...
USDA Plant database
http://plants.usda.gov/java/
Ladybird Johnson Wildflower Center
http://www.wildflower.org/
Plants for a Future
http://www.pfaf.org/user/default.aspx
And you can always do a search for
native plants of Maine for more specific information. Good luck!