I just downloaded Dead Money to my xbox and i was just wondering what a level i should be before i start it. Also any advice on what i should bring so that i could maximize load of items i bring back since i know you can't go back onced finished. Please no spoilers

Start at any level, doesn't really matter.
Go in with nothing on you, leave all equipment back at your house, you won't be able to take them with you anyway.

You can go straight through it at level 1 but I would advise waiting until at least level 6 or 8 so you have a few perks and a better chance of living. If you already have a higher leveled character then you should be fine.

you can't take any of your equipment with you? how does that work, it gets stripped from you at the BoS bunker?

Yes.

When you start the DLC it says that it may be better suited for players level 20 and up. That's a bit much, I did it at 15 or so, but you may want to go up some levels just so you have some decent fighting stats. At one point I nearly ran out of bullets in the DLC, and if I didn't have a high Guns skill I may have ran out. If you're an experienced player you won't have too much troubles though, just make sure to loot what you can find.

I've done it twice now, once at level 24 and once at level 30, and I have to say, having high-end skills and innate upgrades (like the implants) are really helpful in getting a satisfying completion of the DLC. Guns is a very difficult way to go; I'd suggest waiting for a higher level if that's your only weapon skill. Speech is handy for dealing with the companions and prying more of their story out of them. Repair and Explosives are useful for dealing with the scads of traps, while Repair is also necessary for both recycling ammo and making the cool new weapons. Survival is good for making some of the cooking recipes. The list goes on.

Basically the DLC is basically set up to acknowledge and reward all of your character advancements and can provide a challenge all the way up to level 30+, so I wouldn't be in a hurry to take it on when there's so much of the Mojave to occupy your time before that.

I've went through it once and noticed that if you want a certain outcome. you may want to have high speech, repair, explosive skills plus weapons skills. 65+ going in. Lower levels won't have their skills that high It just makes it easier.

i started around lvl 16-18 for the so fights are tough but mangeable, also sneak is really need or you'll get jumped alot.....

The one advantage of doing it with an earlier level character is coming out with a few nice weapons with plenty left to shoot in NV. On the other hand, there certainly are enough good weapons already.

Starting later does make it easier....particularly with your skills and perks.