First let me say that there is no magical solution to automatically clean up audio. It all depends on the particular problem you are trying to address.
Sure there are plugins for various audio editors that can sometimes do a good job and other times have no benefit whatsoever. Again it depends on the 'problem' you are trying to address and keep in mind that some recordings are just plain beyond repair.
Removing clicks and pops are fairly straightforward as the problem is eaily spotted by visual inspection of the waveform; others are not so readily appareht. In general, it just takes time and experience to learn what can be corrected (to some extent) and what is hopelessly lost. Garbage In == Garbage Out is very true when it comes to audio editing.
I'd consider myself in the Pro-sumer category simply because I have a decade of experience with editing audio (I use Sound Forge) but some things are just beyond repair. I've learned a few tricks over the years so if you have any specific issues you'd like to try to make better I maybe could offer some techniques to try.
