The H-Bridge schematic, sorry about the mess.
The print version is in PDF file

My motor works with 15V, but with the TIP31 I can put much more than that.

Print.pdf1 MB

Step 3Schematic

This is the schematic for the connections with the PIC16F877A.

The JP1 is VCC and GND, the JP2 is where you connect the motor, inverter is necessary for this, because the DEMUX work in logical level low, but if you have one thats work in high you can remove inverters ports.

The Pot is the ANALOG input, where I will connect my Joystick.

The PWM is the port RC2/CCP1 and goes to DEMUX.

The DEMUX is very simple, look in the link below for the datasheet.
http://www.datasheetcatalog.com/datasheets_pdf/7/4/L/S/74LS138.shtml