best mac software to create a brochure?

It helps if you explain what exactly it is you want to do.

Will you be going to a commercial printer using either offset or digital presses?

Will the brochure be in full color cmyk?

Will it be a virtual publication such as a pdf or epub?

Have you talked to a printer yet and found what they want?

Pages is OK for printing directly to a desktop printer but presents enormous difficulties when trying to create a job suitable for commercial printing. It lacks crop marks, slugs, adequate color management, can not print spot colors or "specials", show cutouts, it tends to produce black text as cmyk mixes without a lot of hard work by the user and mostly produces unusable pdf files.

Recommended software would be Indesign and Quark XPress both of which require professional training as well.

My recommendation is get a professional Graphic Designer or the printer's DTP staff to do the final work for you ready to press if all the above sounds like foreign gibberish to you.