Welcome to LJ! Watch out for falling emos. :D
I learned all I did about creating LJ layouts on
LJ Designers. The best thing is to read the memories first, as it would probably have almost everything you'd want to do initially covered (background pics, frames, etc.).
LJLayouts has several really good layouts for FREE accounts. You'll want to keep an eye on whether your LJ is using the S1 or S2 styles. When you click on "Manage" -> "Customise", you'll have the option of choosing S1 or S2 styles.