archendekta,

How many seven segment displays do you want to control? If you only need one or two, use a BCD (binary coded decimal) to seven segment IC. Check out this circuit:

http://www.aaroncake.net/circuits/counter.asp

You would replace the 74LS90 with four pins from your PIC to input BCD to the 74LS47. If you're just counting up and resetting, then you could use the entire circuit from above and just use one pin to send a pulse and count up one digit at a time.

Now, if need to control several displays, I'm using a MAX7221 which can control up to 8 common cathode digits simultaneously.

http://www.maxim-ic.com/quick_view2.cfm/qv_pk/1339

It is controlled similarly to the 74HC595 through SPI communication which requires only three pins from the PIC.

If you need to keep it on the cheap side, you can use a 74HC595, but you may need to use transistors or MOSFETs to feed the pins of your seven segment digits if they require more current or possibly voltage than the '595 can handle. An alternate IC is the STP16DP05 or STP08DP05. They are designed to drive LEDs at a set current (so all the segments will be have the same brightness) and allow you to use up to ~20V which you'll need if you decide to use big seven segments, plus they use SPI communication. Another even cheaper IC is the A6278EA-T. I have not used this one, but it about half the cost of the STP16DP05 and is rated up to 17V.

Hope this helps.