Power users are business analysts trained to use QBO to implement business requirements. The skill set for a power user should roughly be comparable to an "Excel power user". If you are comfortable using advanced Excel formulas (e.g. vlookup), pivot tables and such, you should be able to transfer those mental models to QBO fairly readily. That said, the range of skills required for a power user can vary widely:
Document experts should know Word, merge fields, and data well
Workflow experts really should know their business domain exceptionally well,
Scoring experts should be Excel gurus
Matrix experts should be good at if/then logic games
Query experts must know SQL
Plugin developers should know C#, XML, SOAP
Custom UI developers should know XSLT, SQL, JSON, and AJAX
To dive into QBO, we recommend gaining an understanding of the method signatures which underlie everything in QBO, including getting data into and out of the system, workflows, and more. It's always best to start with simple configuration exercises like user management, tasks and documents. As your comfort level increases, consider diving into all of the QBO components:
User Management
Add, activate and deactivate users, reset passwords and add users to teams (Labels)
Add users to Roles and grant access to Organizations to leverage extranet security access.
Roles
Add a Role and grant functional and template-based permissions
Import Routines
Build a basic Excel-based Import to get data into the system
Attachment Templates
Create an Attachment Template and assemble a Word Mail Merge transform or use a data enabled PDF (Adobe Acrobat PRO required; see video below).
Videos: managing documents, new PDFs, document classification
Ledger Templates
Create a Ledger Template that applies to a parent object, i.e. Loan and add Ledger Template Items to the Ledger Template.
Message Templates
Generate a canned Message with a Subject and a Body, with fields merged into the Body.
Schedules
Create a Schedule to be used in a Workflow Polling Step or Report configuration
Process Templates
Add a Process Template that applies to an area of your business
Add Custom Types and Statuses
Workflow
Orchestrate the business process using a Workflow, employing at least one of each Step Type
Videos: create a workflow
Task Templates
Add Questions to one of the Tasks created when assembling the Workflow
Add a standalone task and configure Status-based Routing
Videos: user-defined fields, status routing
Workflow Hold
Add a Hold Template, with a specified estimated duration
Rules Matrix
Build a Worklist Assignment Matrix
Build a Workflow Matrix from the Process Template Summary page
Manage user's work
Configure Smart Worklists that were auto-generated by the creation of Task Templates
Setup Task Auditing through the Smart Worklists
Reports
Add a basic Report-based Statement query
Assemble a Report using the Statement added previously
Convert Report to return an Excel Spreadsheet
Orchestration: queuing
New functionality: filters, dimensions, and plugins
Testing and troubleshooting tips:
Ignore the UI, and query data directly from the browser
Test the UI with Theme/Wrap