I know PhotoShop principles and web design and now i want to learn how to create professional logos
can you tell me about good tutorial or articles or videos that teach me creating logos
Your best bet for Logo creation is to be using Illustrator, you can apply some of the techniques learned here to Photoshop, but it won't be in a vector format.
Hope that helps :)
For some people, anything with a gradient or a swoosh in it is going to be considered "professional" in appearance. For others, it will be considered trite and decidedly amateurish.
If you're serious about pursuing logo design as a profession and are not naturally talented at such tasks, then you should probably start with actual schooling in visual communication. If you just want to crank out the swooshes for the chance to win big on logotournament.com, then the paint-by-numbers tutorials aren't too tough to find.