Deciding what to read next

Instead of posting a book review today I thought I would simply ramble which is much lovlier. I actually do have a question though, how do you decide what to read next?

I have a heard time deciding because I am always torn with what should be my top priority. I have a few ways that I choose but  I want to come up with a pernament and easy solution.

I never know if I should be reading the books I just bought because that was my intention was to read them right away, or if I should be reading books that have been sitting on my shelf for awhile. I think I should but then it think well there still sitting there for awhile so maybe I should read the new ones first. It takes a lot of time to pick a new book this way.

My second delema is the library and gifted books. I know if I go to the library, or borrow a book from a friend I always read that one first. If I am in the middle of another book I will finish it up quickly so I can move onto my borrowed books. Then there is the question of gifted books. Do I read these the same way as I read borrowed books or is it okay to let them sit there for awhile? The reason I am asking is because a friend from work gave me some books for Christmas. I have read one and I have two more to go. I attempted to start reading book number two yesterday but I knew I was not in the mood to start this book and so I put it back for now but now I feel like I should have read it if I am following borrowed book policy.

My final question ( I promise!), is it okay to what I call "shelf cleaner" books before reading goal books. I have some books where I have had them so for long I have no idea where they came from and I am not even sure if I want to read them, but I hate to give away books I have never read so I try to read them and get them off my shelf to make room for more books. Usually once or twice a month I will pick a book or two that I consider a "shelf cleaner" and read it and get rid of it, but should I be putting these books before my reading goal books? My reading goal books I have all year or all month to read but I still feel almost guilty if I put these books before my other books.

HELP!!! Let me know how you decide what to read next, hopefully I can get a solution.