var taskList = new TaskInsertModel[] { new TaskInsertModel() };
var model = new TransactionCreateRequestModel()
{
    EnableLogging = false,
    ResponseIncludes = new TransactionIncludesModel()
    {
        IncludeParticipants = true,
    },
    Transactions = new TransactionCreateModel[]
    { 
        new TransactionCreateModel()
        {
            IsTest = true,
            ProntoID = "Default",
            Description = "Web Services Insert Test",
            Participants = new ParticipantInsertModel[]
            {
                new ParticipantInsertModel()
                {
                    FullName = "John Smith",
                    EmailAddress = "john.smith@your-domain.com",
                    SendRequestViaEmail = true,
					Tasks = taskList
                }
            },
            Documents = new DocumentInsertModel[]
            {
                new DocumentInsertModel()
                {
                    Title = "Web Services Insert Test Document",
                    Source = new SourceModel()
                    {
                        FileBytes = System.IO.File.ReadAllBytes(@"c:\myDocument.pdf")
                    },
                    Tasks = taskList
                }
            }
        }
    }
};
var results = serviceClient.CreateTransactions(GetServiceAuthentication(), model);
if (results.IsSuccessful)
{
    //do work...
}
else
{
    //handle error
}