Mysql query optimization for running site

Hi, I need to optimize my current running site mysql queries. The number of queries are not more than ten. Currently, my site has more than one million entries. It is php and mysql based site. When database was smaller in size everhting was fine. Now database has grown and my script complex queries take a lot of time to complete the request and as a result hang out my server. I need the service of a mysql expert guy who can? optimize mysql queries so that response time for the clients increase. Currently, queries are based on joins and creates temp tables and filesort in mysql.? Any one who is proficient in this work and who can customize mysql database table structure (indexes) and queries for faster respose, please contact me.