I don't have a guide for you, but the concept isn't hard to understand, it just takes more work and time than other hybrids.
You cannot breed them from "scratch" (I'm guessing you mean without hybrids), but the gist of it is this:
Basically, you need a "hybrid red rose" in order to breed blue roses. A hybrid red rose looks no different from a regular red rose, but it's different in that it's parents are one of the following combinations:
- Hybrid Red Rose = Orange and White Rose
- Hybrid Red Rose = Orange and Purple Rose
- Hybrid Red Rose = Red and Purple Rose
Once you have your hybrid red rose, you can start to attempt breeding blue roses with these combinations:
- Hybrid Red Rose and Hybrid Red Rose
- Orange Rose and Hybrid Red Rose
And with two or more blue roses, you can breed more blue roses straight from those.
Hope that helps, and sorry if it's not clear enough!