Marking performance good or bad mostly depends on requirements and of cause of what you are doing.
For example, business expects that search of some data in a web based application returns results in less than 30 seconds.
If your search does it, it is acceptable performance.
When you are loading and transforming megabytes of data and business expectation is that the process run overnight, having it completed in just 30 minutes would be taken as very good performance (even, if it could be done in just 3 minutes).
See, there is some common sence in it.
I know that my opinion may not be supported by some experts here, but in reality there are no such thing as universal Good or Bad performance, or, at least, such defenition is irrelevant in the practicle life. There is acceptable or unacceptable performance and it depends on a particular case.
The first tool to monitor SQL performance you can use would be MS SQL Performance Monitor, which is most likely part of your SQLServer EM installation. There are also many other SQL monitoring tools available (often used by DBAs). You can google for them and read reviews. I can list just some of them for you:
Ignite (from Confio)
Spotlight (from Quest)
there are many more around...
P.S. As you have question about it, I can conclude that someone complained about performance of the system/application in your place, therefore if the reason of it lays within your database you can call it as Unacceptable performance (or bad, if you really like to call it like that). See, sometimes you don't need any tool to judge on it, because if the performance is unacceptable by business, they would not care if some performance tool will call it as "good".:-D
"The only true wisdom is in knowing you know nothing"
"O skol'ko nam otkrytiy chudnyh prevnosit microsofta duh!":-D
(So many miracle inventions provided by MS to us...)How to post your question to get the best and quick help