Best thing to do is go out and give it a try. Experience the adventure. Use the attributes, the list Brdad provided and the last found is always a good indication. You can also look at the logs and see if anything interesting is going on. The harder rated ones might be even harder to find in the winter, but the bugs can be as bad as deep snow and cold.

After you are worn out come back with questions and some one will be able to help.