Brewing 1st Lager, and with Spices

I've made 3 batches of homebrew since buying my kit, adn they've turned out great. They've all been Ales so far though as I don't have any temperature control to keep them cool. However now being up in Boston, the weather is getting cold and I have a room that isn't insulated which usually hovers in the 40s during the winter which would be PERFECT for lagering.

So I'm planning on making my first attempt sometime this week at a lager. I have some home grown Cascades I want to use for a dry hop as well. But my main question is how would I use spices, such as cinnamon, ginger, vanilla, in my brewing? I've read that just a few teaspoons or tablespoon of each spice is usually enough for 5 gallons but how do they mix? I know that you add them with about 10 mins left of the wort boil too.

Can you use grains for lagers, and is it all the same mashing process of around 158F?

I don't beleive I have even made an ale at that high of a mash temp.
Most of my lagers are mashed at 152 and lower for better fermentability for 90 minutes. I also like them on the dry side.

Well the temperature may have been off, I have a great book for homebrewing that details the procedures so that's not the problem.

My main concern is finding out how to brew with spices to get a balanced flavor. Such as which spices will overpower others, and how to blend them together

I haven't used spices in any beer yet, but it is best to use a little at a time until you get what you want. Once in there it can't be removed.
Sorry I cant help.