Below I am grabbing data off a Workflow with a browser enabled Infopath Form and loading a separate list.

public Microsoft.SharePoint.Workflow.SPWorkflowActivationProperties workflowProperties = new Microsoft.SharePoint.Workflow.SPWorkflowActivationProperties(); 

  private void onWorkflowActivated1_Invoked(object sender, ExternalDataEventArgs e)
        {

              ...
                //Save the identifier for the workflow
                workflowId = workflowProperties.WorkflowId;

                // InitiationData comes from the initialization form
                XmlDocument document = new XmlDocument();
                document.LoadXml(workflowProperties.InitiationData);

                // Get Data Off Of Init Form
                XmlNamespaceManager ns = new XmlNamespaceManager(document.NameTable);
                ns.AddNamespace("my", "http://schemas.microsoft.com/office/infopath/2003/myXSD/2006-12-05T20:04:17");
                managerUsername = document.SelectSingleNode("/my:flowFields/my:managerUsername", ns).InnerText;
                managerFullname = document.SelectSingleNode("/my:flowFields/my:managerFullname", ns).InnerText;
                reviewType = document.SelectSingleNode("/my:flowFields/my:reviewType", ns).InnerText;
                reviewComments = document.SelectSingleNode("/my:flowFields/my:reviewComments", ns).InnerText; 

                using (SPSite siteCollection = workflowProperties.Site)
                {
                    using (SPWeb web = siteCollection.OpenWeb())
                    {
                        SPList EmployeeReviewList = (SPList)web.Lists["EmployeeReview"];                     // Specific List
                        SPListItem EmployeeReviewItem = OptimizedAddItem(EmployeeReviewList);       // Add New Item to List
                        EmployeeReviewItem["Review Name"] = reviewType;                                            // Update elements of new item
                        EmployeeReviewItem.Update();
                    }
                }  

  ... }

       //cf.  http://blog.robgarrett.com/2009/02/25/efficient-way-to-add-a-new-item-to-a-sharepoint-list
        public  SPListItem OptimizedAddItem(SPList list)
        {
            const string EmptyQuery = "0";
            SPQuery q = new SPQuery { Query = EmptyQuery };
            return list.GetItems(q).Add();
        }

Credit due for OptimizedAddItem(): http://blog.robgarrett.com/2009/02/25/efficient-way-to-add-a-new-item-to-a-sharepoint-list/