Barcode printer are available, with built-in bar code fonts. You can interface such printer to an 8051. All you will have to interface such printer to an 8051 (easy if you chose a serial port version of printer).
The praticular printer's manual will have necessry information on how to select the font and how to send data (to be printed).

Regarding barcode reading, ther are commercial barcode readers which have Rs-232 interfce. These will decode the barcode and output the data.

Have a look at EPSON website and look for "POS" (point of sale) equipment. ALso search for IDTech website, they have some nice barcode readers available.