Recommended for beginnersHere is a shortlist of links recommended for beginners.
Everything in the section
Language creation, grammar, syntax and vocabulary, and especially the
Language Construction Kit:
http://www.zompist.com/kit.html - a "manual" for creating (naturalistic) languages. A similar website is also
Wikibook: Conlang https://en.wikibooks.org/wiki/Conlang - it's more of a step-by-step tutorial at various levels but really useful for beginners.
Highly recommended is also everything in the section
IPA, X-SAMPA, phonology, sound changes, and especially the following:
International Phonetic Alphabet (IPA):
http://en.wikipedia.org/wiki/International_Phonetic_Alphabet - a Wikipedia article on the IPA; scroll down to chapter 5:
Letters for symbols and audio recordings; and
Extended Speech Assessment Methods Phonetic Alphabet (X-SAMPA):
http://en.wikipedia.org/wiki/X-SAMPA - a Wikipedia article on X-SAMPA.
Another highly recommended link to read is
Glossing rules:
http://www.eva.mpg.de/lingua/resources/glossing-rules.php - the rules for glossing any language, natural or constructed.
If you're looking for an online wiki or a dictionary, the following is recommended:
Linguifex:
http://www.linguifex.com/index.php?title=Main_Page or
FrathWiki:
http://www.frathwiki.com/Main_Page to set up your pages for your conlang(s); and
ConWorkshop:
http://conworkshop.info/feed.php - an online dictionary for conlangs, includes a forum and many useful tools.