Alix, the first time I tried it, I thought it was absolutely wretched stuff. But I quickly learned that it was because I had not bought or stored it properly, and it had gone rancid. The reason I am throwing out this caveat is because I wouldn't want others to make the same mistake I did. I could've easily dismissed it had I not looked into it a little further.
It turns out that flaxseed oil is very delicate. It must be fresh and it must be refrigerated because otherwise it will quickly go south. It should be treated more like dairy than cooking oil. Furthermore, it shouldn't be used for cooking at all because it has a very low smoke point and burns easily (not to mention heat destroys the healthy aspects). Make sure that the place you buy it sells it in the refrigerated section and check the expiration date. I've read some people even go so far as to freeze it, but I've never tried that.
Having said all that, if your oil is fresh and properly stored, it will have a somewhat nutty/grassy kind of flavor. Not at all objectionable. It also has the ability to be somewhat chameleon-like and blends with other flavors really well.
But I would recommend only buying what you expect to use within a couple of months.