Wash and dry your fabric.
My view here is that you want to abuse your fabric as much as possible now and then baby it after it becomes a garment. So wash it on hot, add a nice amount of detergent, set your machine to extra agitating**. This will (hopefully) get all of the sizing out and shrink the fabric as much as it’s going to shrink BEFORE you try and make it into a garment. After this is a garment I normally will wash in tap temperature water and hang dry.
When your fabric comes out of the dryer you should iron it, especially if it got very creased along the selvage. It’s not required, but it can make cutting out the pattern a bit easier to manage.
**If you’re working on a different fabric, say silk or something loosely woven, I’d be careful with this step. In some cases, especially shot silk washing the fabric may cause the dyes to bleed and your lovely shot silk (or sometimes shot linen) will ends up a muddy middling color instead of the gorgeous color changing fabric you intended to use. Washing a test swatch is always recommended when working with a new-to-you fabric.
If you end up with a fabric which you can’t wash then keep in mind you’re signing up for dry-clean or spot clean only. Lord help the loved one who simply tosses a garment into the washing machine willy nilly.
I personally don’t bother sewing up the raw ends. If I were washing something more loosely woven I’d run a zigzag along the ends or french seam the beginning to the end to keep the fabric from raveling.
If you got the Fabric-store.com “signature finish” they claim that it’s pre-shrunk. I still recommend washing it. I’d rather KNOW that I’ve done my due diligence rather than depend on the vendor.
[A note here: I bought Cobalt linen.. and then noticed that I liked the way cobalt paired with some coral wool I have set aside for my next dress MORE than I like the “Dress Blue” I had originally set aside. The difference doesn’t photograph well.. but believe me, the coral with the Cobalt was better. Also, Dress Blue is the “so blue its almost black” and I think the right seam treatments can really bring that out. So I changed this project to use the Fabric-store.com IL019 in “Dress Blue” I had tucked away in my stash.]