Help needed please!

are you planning on using a microcontroller ? or a discreet logic design ?

Discreet logic design chum, whats your feedback?

I was thinking along the lines of a crystal oscillator feeding a couple of 4060's to give you a tick tock...and a few ripple counters to give you the required steps for the LED's.

Remember though that when counting using LED's, the sixth LED denoting the seconds, will only be lit for a 1sec period before the roll over...

For extra flashiness, you could add a few diodes, resistors and a couple of transistors built as a multivibrator that gets triggered by the count going past 5 mins, set the resistors to vary the frequency of the multivibrator using a couple of the ripple stages and feed it to a small speaker through a capacitor...then it plays a wee tune of sorts when it's done it's 5 mins

just a thought

I'll leave the ingenuity of how to construct it all, in your hands, as it's your college work and not mine