The following can work. You can google for them and see how they work.
driver.findElement(By.id("id"));
driver.findElement(By.cssSelector("cssSelector"));
driver.findElement(By.name("name"));
driver.findElement(By.linkText("linkText"));
driver.findElement(By.partialLinkText("partialLinkText"));
driver.findElement(By.className("className"));
driver.findElement(By.xpath("xpath"));
I am sure some of them will be useful. Please let me know if you want more info. The easiness of using them is in the order which i have mentioned.