Practical and helpful SAP WORK FLOW Stuff to assist those who seek to know more about the SAP Business Workflow. 

SAP Business Workflow can be used to define business processes that are not yet mapped in the R/3 System. These may be simple release or approval procedures, or more complex business processes such as creating a material master and the associated coordination of the departments involved. SAP Business Workflow is particularly suitable for situations in which work processes have to be run through repeatedly, or situations in which the business process requires the involvement of a large number of agents in a specific sequence.

You can also use SAP Business Workflow to respond to errors and exceptions in other, existing business processes. You can start a workflow when predefined events occur, for example an event can be triggered if particular errors are found during an automatic check.

SAP provides several workflows that map predefined business processes. These workflows do not require much implementation. 

SAP Workflow Reference Book
SAP Workflow Interview Questions, Answers, and Explanations

Practical Workflow for SAP - Effective Business Processes using SAP's WebFlow Engine

Workflow Management With Sap Webflow: A Practical Manual

Workflow Frequently Asked Question
Implementing Workflow FAQ
Workflow FAQ on Settings and Customizing
Tcode For Listing All The Workflows

Purchasing
Trigger WF from MIGO
Purchase Order and Sales Order Workflow
Workflow of Purchase Requisition Release Strategy

General
swi14 to Check Statuses of Workflows
Users Assigned To Task Do Not Receive Workflow Messages
How to notify users that they've got a Work-item/message?
Workflow Debugging
Finding out the Object Types involved
Binding from Task to Custom Method
Workflow bottlenecks
How to display company logo in workplace (work item preview)?
Create Object SWU_WFML_INBOX
Generating Sub Workflow
How to Delete Documents in Workflow?
Workflow Items Sent To Everyone If Agent Not Determined
Difference between Rule and Role

ABAP
Reading attribute of a BOR (Business Object)  in ABAP

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