Once you understand our climate, you'll find western Oregon a great place to garden; many plants grow really well here.  We're famous for rain, our winters and spring are very wet, but in July and August, and sometimes into fall we get no rain, a mini-drought.  Our native trees and shrubs have adapted to that schedule, some even resent summer watering, but it can affect fruit tree production.

One result of our long wet springs is the prevalence of pear and apple scab, which your pears show evidence of.  Scab is caused by the fungus Venturia inequalis (apple) and V. prima (pear).  Infection is weather (moisture) driven.  The fungus overwinters on infected leaves and fruit.  When we have a cool wet spring the infection rate goes up dramatically.  The fungus forms spores in the spring, in cool wet conditions about the time when flower buds are forming.  The spores are released into the air and  air currents move them onto the flower and leaf buds.  The spores germinate causing the primary infection.  Secondary spores are then produced on infected leaf or fruit surfaces 8-17 days later.  The disease continues to spread until weather conditions dry. 

To control pear scab remove the infected leaves and fruit from under the tree in the fall after the leaves have been shed.  Either compost the leaves and fruit a good distance from the tree or dispose of them.  Lime and fertilize underneath the tree to speed decomposition  of any leaves left over.   In the spring if you have had a severe infection, it's good to spray the tree starting at the time the buds begin to break, then again a month after petal fall with a fungicide, like sulfur, bordeaux mixture, neem oil or copper.  This article gives more information,  Apple and pear scab  http://ipm.ucanr.edu/PMG/PESTNOTES/pn7413.html

You may also have insect in your pears.  The black spot looks like an insect entry hole.  There are several insects that like pears.  One good method to find out which ones you have is to place sticky traps in your trees in the spring.  The insects that get trapped can be identified, and a control program begun.  Control methods are based on the insects you have.  Using a dormant oil spray on a sunny day in winter can smother the eggs of many insect pests.

Identifying the varieties you have can be based on appearance of the fruit, and timing of fruit production.   Bartlett pears are the earliest, ripening in early fall.  They and Comice pears have smooth skin.  Bosc pears have a rough skin.  This article, Varieties - pears  http://treefruit.wsu.edu/web-article/pear-varieties/ should help you determine which you have.  You can also send pictures to us to help you identifythem.

Finally, pears are somewhat unique in the harvesting process.  Tree-ripened pears ripen from the inside out and become mush.  Pears should be picked when full size, but not ripe.  After harvesting them put them in a cool place like a refrigerator for a few days.  At that point you can remove them as you wish and they will ripen at room temperature into lush, sweet fruit.  This article gives more compete information, When to pick and how to ripen pears to perfection  http://extension.oregonstate.edu/gardening/node/413.

The  Home Orchard Society  http://www.homeorchardsociety.org/ is a good source of help for fruit trees, care, pruning, etc.