Is a clean install of Mavericks needed?

[tomwalsh77]

After upgrading to Mavericks from Mountain Lion my iMac doesn't seem as snappy and I'm getting the odd beach ball and iTunes sometimes seems a little sluggish when syncing my iPhone. Also when I shutdown the desktop background stays visible as well as part of the dock and this doesn't look right to me. I'm wondering if a clean install of Mavericks might eliminate these issues?

I'm quite new to Mac so if it is necessary to do a clean install, what are the steps I need to take to do this?

Thanks.