Hi everybody!
Please I need help with my homework.
I have to write an email to a hotel asking for more information.
I don´t know how to start the salutation, and I don´t know the name of the hotel manager either.

I think in this options:

Dear Sir/Madam:
Dear Mr/ Mrs:
To whom it may concern:

Hello Sofi,

Welcome to EnglishForward!

In answer to your question, 'Dear Sir/Madam' is perfectly ok to use since you are writing to a hotel.
To whom it may concern,
I heard the name of your Hotel and need more information.
Students: Are you brave enough to let our tutors analyse your pronunciation?
Thank you all! Emotion: smile

I am a student of English from Argentina, and I think this web is great!
Hello Sofie,

I'm a great fan of Argentine Tango & am dying to learn it. Have not seen a dance so passionate and so intense!! Hope to learn it someday! Do you know how to Tango? Emotion: smile
a que facultad vas??
Students: We have free audio pronunciation exercises.
What does that mean?
Begin like this:
Dear Sir / Madam,
I want... or something like thins

and in the ending:
Many thanks. I look forward to hearing from you in the near future.
Yours faithfully,