The search queries report has just been changed in Google Webmaster tools Google named it Search Analytics (Beta). I saw it today morning IST time, it seems very useful because the bifurcation of data to be analysed there is also option to go back to standard search query report.
Webmaster Tools sets training on various aspects and website concerns including how to basic and advance of website crawling, indexing and trouble shooting.
Hyper Text Transfer Protocol or HTTP response status codes are returned when search engines or website visitors make a request to a web server. These codes with three digit value indicate the response and status of HTTP requests. The http response starts form 1xx, 2xx, 3xx, 4xx and 5xx for 1xx I suggest you to do some search hear I am explaining you the rest of the http status codes.