Inserting

Inserting Rows

Selection.EntireRow.Insert 

Inserting Columns

Sheet1.Range("A:A").EntireColumn.insert 
Sheet1.Range("A:A").Insert 

Deleting Rows

Rows(4).Delete 
Rows(4:4).Delete 

Rows(4:4).Delete Shift:=xlUp 
Rows(4:8).Delete Shift:=xlUp 

Cells.EntireRow.Delete 
Selection.EntireRow.Delete 

Deleting Columns

Cells.EntireColumn.Delete 
Columns("A:D").Delete Shift:=xlLeft 

Deleting Empty Rows

This uses the COUNTA worksheet function to determine if a row is empty.

Sub DeleteEmptyRows() 
Dim lLastRow As Long 
Dim lRowNo As Long 
    lLastRow = ActiveSheet.UsedRange.Row - 1 + ActiveSheet.UsedRange.Rows.Count 
    Application.ScreenUpdating = False 
    For lRowNo = lLastRow To 1 Step -1 
        If Application.WorksheetFunction.CountA(Rows(lRowNo)) = 0 Then 
           Rows(lRowNo).Delete 
        End If 
    Next r 
End Sub 

Deleting Blank Rows in a Selected Range.

Type:=8 argument specifies a Range object; input value must be a range.

Sub DeleteBlankRows() 
Dim rng As Range 
Dim selectedRng As Range 
Dim iRowCount As Integer 
Dim iForCount As Integer 

Set selectedRng = Application.Selection 
Set selectedRng = Application.InputBox("Range", , selectedRng.Address, Type:=8) 

iRowCount = selectedRng.Rows.Count 
For iForCount = iRowCount To 1 Step -1 
    If Application.WorksheetFunction.CountA(selectedRng.Rows(iForCount)) = 0 Then 
        'Delete entire row.
        selectedRng.Rows(iForCount).EntireRow.Delete 
        'Delete partial row.
        'selectedRnd.Rows(iForCount).Delete
    End If 
Next 
End Sub 

Deleting All Visible Rows

This deletes all the visible rows between 1 and 100.

ActiveSheet.Range(Cells(1, 3), Cells(100, 3)).SpecialCells(xlCellType.xlCellTypeVisible).EntireRow.Delete