ignore the post count but i am quit noob in this forum. i need a couple of info regarding sig and avatar

1)how big can my avatar be and what is the recommended size

2)where do i go to load up my avatar after webhosting it in a webhosting site

3)how big can my sig be and what is the recommended size

3)where do i go to load up my sig after webhosting it in a webhosting site

4)any recommended webhosting site i need to be aware of??

pls help me out here