Hi ShaamAnsu.
Yes, I encourage you to post items -- your own work is preferable though! If it's someone else's work you will need to give proper credit, and also make sure you have explicit permission to share it here. If you are absolutely positive the work is public domain then you may share it with credit given to the piece's creator. (If we find that something has been shared without permission it will be removed.)
Things that you would like to be discussed should be posted in the Forums. Other things can be submitted through the links in the User Menu (usually on the left of the screen.) News items are usually announcements of some sort, and most everything else goes in Articles. I also encourage everyone to share topical weblinks for our Links section.
If you're trying to post pictures in the Forum you'll find there are limitations on the size of the picture -- it won't take images that are more than 499 by 499 pixels, or if they are larger than 50 KB in size. Once you've use the Browse button to select the picture to include, you should click the img button beside the Browse button to pop the code into your Forum post.
You can do test posts in the Test Posts section as you figure out how to use the various features of the Forum.
Feel free to ask any questions that come to mind. The only bad question is the one we refrain from asking!
Ben Gruagach