Once I was at the liabray and i found a 5000 page book on J.R.R Tlkien translation guid to elfesh
I'm only a fluent reader in Drawfish so I'm not a fan of elfesh
Try Ardalambion (folk.uib.no/hnohf/). It's a site with many materials on Quenya and Sindarin, including wordlists for both languages and a course for Quenya :) I suggest you read through the elvish texts and their translations first to familiarise yourself with the way the language "feels". If you want some practice with writing Quenya, the Neo-Quenya Wiki (www.neo-quenya.wikia.com) can provide a platform for you to do so, the number of editors on that wiki are not many, but are willing to help out if you ask.