Mmm, if you need knowledge, you just have to find it on the Internet (Wikipedia, Google, etc... as usual ;)
If you have problems finding what you need this site is a great resource: http://www.searchlores.org/; it has a lot of information about search engines and Internet related stuff, unfortunately it hasn't been updated in a while and it takes a while to fully read it (I haven't read it all myself ;)
If you need help, practice is all you need: as Spoodle58 said, you can pay a visit to the linked sites (WeChall is a good place to start) and hone your skills :)
To Spoodle58: This website gave me all I needed for regexes (http://www.regular-expressions.info/tutorial.html) and here's a nice cheatsheet (http://www.addedbytes.com/download/regular-expressions-cheat-sheet-v1/png/).
Hope it helps,
monnino