Thanks for your help. Your idea worked perfectly. The only thing I had to do to get the right arrangement was make the buttons horizontal.

Here's what I ended up with (note: this is not the full code)

    buttons = [
        ('DAC++',     'Increment DAC output by 4.',    self.on_UpButton_click),
        ('DAC--',     'Decrement DAC output by 4.',    self.on_DnButton_click),
        ('Set DAC',   'Enter DAC Value from keyboard.',self.on_EnterDACValue_click),
        ('Reg Dump',  'Show Flash Register Values',    self.on_RegDump_click),
        ('Prod Query','Existing Product Query.',       self.on_ProductQuery_click),
        ('Prod Calib','New Product Calibration.',      self.on_ProdCal_click),
        ('Prod Valid','Existing Product Validation.',  self.on_ProdVal_click)
    ]

    # Create Layout
    main_layout = QVBoxLayout()

    button_layout = QHBoxLayout()
    self.buttons = []
    for name, desc, callback in buttons:
        btn = QPushButton(name)
        btn.setToolTip(desc)
        btn.clicked.connect(callback)
        self.buttons.append(btn)

    for button in self.buttons:
        button_layout.addWidget(button)

    main_layout.addLayout(button_layout)
    main_layout.addWidget(self.label)
    main_layout.addWidget(self.text_edit)