Oh, yes, be sure to normalize your tables, at least 3NF.

I would stay away from GUIDs as a primary key, especially if it gets defined as the clustered index.  For me there needs to be a good reason for using...

Was I taught wrong regarding normalization?  I was taught that you normalize to a point, say 3NF, then de-normalize where appropriating knowing the trade-offs and possible issues that you would...

Or, have a calendar table and reference it by the date and have it break the dates into constituent parts.

I'd rather store the date as a date and use computed columns if I need the month, day, or year separately on a regular basis.

Definitely would help to have the DDL (CREATE TABLE statement) for each of the tables used in the query.  Would also help to see the execution plan for the query, uploaded...