Blocking on fractional factorial designs is relatively easy in Minitab
as long as we let Minitab supply the effects to confound with block.
As usual
for a fractional factorial design, enter the total number of factors
you want to analyze in the Number of Factors box in the Create Factorial
Design menu.  Select Designs and choose the appropriate fraction (full
factorial, 1/2 fraction, etc.) you would like to set up.  Select the
appropriate number of blocks, return to
the main dialog box and, as usual, unselect the Randomized Runs box.
Return to the main menu, click OK and your fractional factorial design
will be selected for you.  Minitab will print the alias structure of
the preselected design in its Session window.  Note that the design
generators for the fractional factorial are listed first and then
the block generators are listed.  In the worksheet, the runs are 
grouped by block.

If you have to specify a custom block (as in the exercise we discussed
in class), you select 2-level Factorial (Specify Generators)
in the main Design dialog box.  After selecting the design, select
Generators and then enter the block generators in the Block dialog
box.  In our example, the default half-fraction with two blocks had 
design generator D=ABC and block generator AB 
but we needed D=AB as our design genrator and AC as our block 
generator.  In that case, we simply enter D=AB in the design generator
box and and BC in the block dialog box.

After running your experiment, analysis proceeds in the usual fashion.
Note that Minitab doesn't treat the block like an effect so that, for
instance, the effects plot has d-1 fewer effects than usual (where d
is the number of blocks).