It might help to know what kind of test function you are looking to perform. There are test planning tools, functional (gui) automation tools, performance/load testing tools, and defect tracking tools. All these tools can help you accomplish specific testing tasks. There are many vendors of tools too and a thousand varied opinions about each of them.
Steps to consider:
1 - Determine what you need a tool to do.
2 - Evaluate if a tool will work for your environment
3 - Evaluate if you can afford the tool
If you have deeper questions, feel free to contact me by e-mail.
Also when making a choice between various tools is a vital aspect contributing to the success of automation. Check out this article.
<A HREF="http://www.stickyminds.com/sitewide.asp?ObjectId=1798&ObjectType=ART&Function =edetail" TARGET=_blank>A Five-step Process for Comparing, Evaluating, and Choosing the Right Tool
: Elisabeth Hendrickson</A>
never say die
Life, that dares send, A challenge to his end,
And when it comes say, Welcome friend.