Please follow these simple steps:

1) open catalog > category > default category and set "Is Anchor" = "Yes"

2) open catalog > attributes > manage attributes > manufacturer
and make sure it contains some options like "samsung", "canon", etc .

3) open catalog > improved navigation > filters and press "load".
You'll see the "manufacturer" filter. You can configure all texts and logos here.

4) open catalog > improved navigation > settings > brands
and set Brand Attribute Code to "manufacturer"

Clear the cache. Now a new brand page like http://example.com/canon.html is available.

To create a page with all brands, please open cms > homepage  (or any other page) and add a block:

{{block type="amshopby/list" attribute_code="manufacturer" columns="2" template="amasty/amshopby/list.phtml"}}

as per the user guide.