Biq is really quite simple to use. Play with the settings in the control panel, then click on the Draw button to redraw the texture. Click on the yellow diamond with the "?" to get back to this page.
The First Two Settings
The first two settings are called Variant and Repeat. Repeat is the maximum tile size, which means that the texture will be guaranteed to repeat after that many pixels horizontally and vertically. It might also repeat at a smaller interval. If you want to see (and perhaps save) a single tile, check the checkbox labeled Tile next to the Draw button.
Changing the value of Variant will give you another variant of the texture. If you make the Variant larger than the Repeat, you'll see the same textures again, but it won't do any harm.
Saving Your Work
To save your texture, right click on it and select "Save image as..." To save your settings, go down to the gray bar underneath the texture and either copy the first link there, or click on it and bookmark the new page in your browser.