I'll use the opportunity to list a few resources that people might find useful:
The Language Construction Kit. It's written mostly for newbies starting out on this vice. Yes, vice, because conlanging is addictive (ask Tolkien).
The Index Diachronica. It lists sound changes by family and sound, so if you're evolving your conlang from another, it gives you a good idea on what would feel natural.
The International Phonetic Alphabet chart. You don't need to know the IPA to make your own conlang, but it's a great way to refer to the sounds that you might include in your conlang.
And while I don't plan to be active on moderation duties in this community, for everyone here: don't be afraid to ask for my help on questions regarding phonology and evolution! I have a decent grasp on both matters, I did use them for my own conlangs, and I enjoy talking about this stuff.