MySQL: getting latest record

My application is that I am getting the latest quote for a price where more than one quote may have been made. I've got a timestamp colum and I want to get the latest record where certain columns have certain values. Eg SELECT * FROM MyTable WHERE Field1='test' ...? something about the timestamp I may also have an OR in the condition, like WHERE Field1='test1' OR Field2=test2'... 'test1' and test2' would be different products. Do I have to use ASCending or DESCending on the timestamp column and LIMIT? Never done this before so suggestions gratefully received. Thanks, John