I July had, according to Google Analytics 5000 unique visitors.
Is it unique ip's or also unique cookies?

Unique Visitors represents the number of unduplicated (counted only once) visitors to your website over the course of a specified time period. A Unique Visitor is determined using cookies.

coming to the theoretical part of google analytics, we can understand by reading, but the same how can you implement practically by looking on the figures inthe google analytics chart. Wht all variations or analysis we can make by just having a look on the Google analytics information that can help us in optimizing pay per click campaign management.

Can anyone help me out, or let me know, based on what type of analysis from the google analytics informaion, we can increase the ROI?

you set up campaigns and measure their conversion... the ones that are profitable you keep and the others you drop - or change the ad or landing page

you should be constantly testing