Importing sheets from XLS and customizing fields/usage

Importing sheets from XLS and customizing fields/usage

I am new to this and trying to use the free Zoho CRM for a basic cold call log. I have currently been using an Excel Spreadsheet which works, but the amount of call data and call notes are starting to get cumbersome. But, when I import leads from my Excel Spreadsheet into Zoho, I only get the 1st sheet. How do I capture the other sheets?
 
I also dont see a way to organize the leads other that alphabetical. Each of my "sheets" represent a separate "call list" and I would like to be able to see and work on each "call list" separately. Can this be done?
 
Is there a way to customize import fields with the free version? (ie Adding a field for Assitants Name, or Time Zone, or an Affiliated Chamber or Association, etc.)
 
Thanks for the help!