Using the search button would have been your first choice.
But to add an avatar (the picture under your post name) you have to have 50 posts or more and then you can select one or upload one in the user cp options. and then under edit options.
As for your sig(picture under all your posts), you take the image you want to be displayed and find a host and then under user cp again under edit profile, add [.img]link to your sig[/img] keeping in mind to remove the period in the first .
That should do it. And now you owe me $20 for my services. :D