is the cedar completely dry? Can you take a scrap piece of cedar and wallop it with a sledge hammer and no moisture surface?
If it is dry, then seal it. Dry wood will absorb more sealer and protectant than wet wood.
John, if you want to maintain that golden color of new cedar, you will be committed to the life of the deck in maintaining that. Many products out there like Thompson's are just cosmetic and don't last too long, meaning maybe 6 months depending on your heat and sun penetration.
Wolman, the developer of Wolmanized Treated Wood, has some very good products out there that will give you a good two year protection then re do it. This product sells for about $25 a gallon.
Another product by the Flood Company called CWF-UV works great. It comes in many colors and even clear. It penetrates and soaks in, its not a topical thing. It sells for about $15 a gallon and the first coating will be like painting a sponge. So be prepared for one gallon not to go to far.
What I found being in the deck business is that any protectant that you spray with a deck sprayer on the deck is not worth its salt. If you have to brush it on, then its good. Get an old brush and slop the stuff on and then work it in.
At some point you will forgoe this work and let it turn grey. When you do this you can always bring it back with a power sprayer and bleach.