Originally Posted by Surferbruce

you can get grease at any auto parts store. i've been using a tub of mobil 1 synthetic grease for over a year (its almost gone finally) with great results.
chances are it's your bottom bracket being dry- not the internals, but the threads that hold it in the frame. to remedy, you need to remove the cranks, remove the bottom bracket, clean it and the bottom backet shell (frame) and grease up the threads on the bb and the shell and reinstall everything.
of course it can be many other things. try a bit of grease on the skewers, as well as the drop out faces on your forks and rear end of the frame.
pedals can be a culprit too. so can the cleats on your shoes.
i would suggest you get a good repair book, like park tools big blue book, or zinns art of maintenance. even if the lbs does stuff for you, you'll know what they're talking about.