Ah, Grey Company is alright for the odd word or two - but it mixes Quenya and Sindarin like nobody's business and what you would be 'saying' would by no means by very accurate.
Here are a few more:
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http://www.jrrvf.com/hisweloke/sindar/index.html
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http://www.councilofelrond.com/modul...ary&file=index (- the council of Elrond dictionary mentioned before)
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http://www.arwen-undomiel.com/elvish/eng_to_elv.html
Not being exactly an elvish expert myself, I am not sure of the general consensus of these sites, but they do the job.