The rolling r (and rr)

[ElDanés]

Yesterday I read in one of my Spanish grammars that the rolling r's and rr's are made by trilling your tongue on the back of the teeth (i.e. dental), for the r, once, and for the rr, two or three times. But normally are rolling r's and rr's said to be made by trilling your tongue on the alveolar ridge (thereof it's formal name, an alveolar trill). Now I am wondering which of them is the correct way of doing it, or if it differs from speaker to speaker, and dialect to dialect?
Speakers (also of the English language, and other languages as well) tend to pronounce L's differently as well, some hold their tongue on the back of the teeth - and others at the back of the alveolar ridge. There might be a difference with the pronunciation of r and rr, as in the example, as well.
I know that some speakers of Finnish make their rolling r's from far back in the mouth, possibly as a velar- or uvular consonant, while others do it in other ways. So, again, it's possibly the r and rr are pronounced differently.

I tried checking how I pronounce them, and I'm trilling on the alveolar ridge, and, even if I really try, I can't make my tongue trill on the back of my teeth.

Some clarification would be good!

¡Gracias!

[Tomisimo]

In every dialect of Spanish that I've come in contact with, the trilling is done on the alveolar ridge (the bump right above your front teeth). I think that particular grammar book you have is not to be trusted.

[Rusty]

Agree with David. You don't place your tongue on the back of your teeth, but on the alveolar ridge instead.

[ElDanés]

¡Una rápida y buena respuesta como siempre!

I guess you're right, but I think I will continue using the book though.
Hopefully it doesn't have other factual errors.

Edit:
Thanks to you too, Rusty, for a second clarification.

[Tomisimo]

Using a few different grammar books instead of only one might be a good idea.

I also dug up an old post I made concerning the pronunciation of the "RR".

[Rusty]

Originally Posted by ElDanés

¡Una rápida y buena respuesta como siempre!

I was going to correct the first adjective, but you caught it. Good job with your Spanish!

Rely on native speakers (through movies, songs, etc.) for pronunciation. Let's hope the book doesn't steer you wrong in other ways.

[ElDanés]

Originally Posted by Tomisimo

Using a few different grammar books instead of only one might be a good idea.

I also dug up an old post I made concerning the pronunciation of the "RR".

Yes, true. At the moment I'm using two ("La gramática" and "Ny Spansk Grammatik"; both in Danish) and I'm planning to buy one in English. Any suggestions? I'm not looking for a book which teaches me Spanish, but simply one I can use for looking up grammar - a real grammar book.

And thank you for the link!

(A quick off-topic question: how to do translate "to you too," as in "thanks to you too"?)

[ElDanés]

Originally Posted by Rusty

I was going to correct the first adjective, but you caught it.

I knew you were, so I edited it the fastest I could.

Originally Posted by Rusty

Rely on native speakers (through movies, songs, etc.) for pronunciation. Let's hope the book doesn't steer you wrong in other ways.

Yep, but in this case I thought it would be hard to hear if a speaker use a dental- or alveolar sound.

[Rusty]

gracias a ti, también

[ElDanés]

Gracias otra vez, Rusty.

I'm still not able to give you any reputation, sorry.