Business software please

I am getting ready to finally attempt this year to start to automate my business. Right now I have all my client intake sheets in an A-Z file so I can at least locate a client's info if I need it. Archaic - I know, huh! But I would seriously like to see what software could help me know from a phone number which client is calling, or allow me to know at a glance that this particular client came in about a month ago and how many times he has come in over the last year, or a way to be able to pull up a list of all of my female clients with a couple clicks, etc. It would be nice to have something to keep track of what income is coming in also and more. In other words, would like to stop being stalked by all these papers in my office and put everything on the computer. What software are you using, where did you get it, and how much does it cost?