I am apparently totally lost as I can't seem to find out how to raise a characters Force Raiting. Could someone please give me a page reference, and if possible a short summary?

Many of the specialisations have, rather than a +1 to a characteristic, a +1 to Force Rating. Mysic: Seer (p53) is one example.

You have to make your way through the talent tree to the Force Rating talent. It's usually (but not always) in the fifth row.

Lightsaber Forms usually don't have this talent (the exception being Niman,) because they focus on martial prowess rather than training in the use of the Force.

Many of the specialisations have, rather than a +1 to a characteristic, a +1 to Force Rating. Mysic: Seer (p53) is one example.

Aaah, I didn't think to look through the Talents, thanks.

So Dedication can't be used instead to raise the Force Rating?

No dedication is for attributes.
Force rating is for force rating.

To get more than a 2 in most specializations means buying another specialization to get access to another force rating talent. The exceptions are the trees with 2 force rating. But those do not have dedication.

Also, there's only one of those 2xForce Rating specializations. But yes, Force Rating is Force Rating, not an attribute or characteristic or whatever you want to call it.

No there are 2. Sage. And mystic.

So it is. My mistake.

So Dedication can't be used instead to raise the Force Rating?

Nope, and never could since the EotE Beta, no matter how much folks back then wanted it to so that they could pump their Force Exiles up to Force Rating 7.

As Daeglan noted, Dedication only applies to raising Characteristics. Force Rating isn't a Characteristic, and thus exempt from being affected by Dedication, just as the Force Rating talent can't be used to raise anything other than the PC's Force Rating.