Here is a goblin deck i've built, still looking for a few things for it like a Chieftain and Coat of Arms, but just wandering if this is a good start.

http://deckbox.org/sets/197684

As you've said, this is screaming for Goblin Chieftain and Goblin King. Goblin Caves is another good option for pumping up their toughness (it would be sad to see all those goblins thwarted by a single Circle of Flame).

Why include Battle Hymn? The beauty of most goblins is that they're CHEAP. If you're really looking for mana ramping for red, Geosurge and Infernal Plunge would be much more helpful early on. Battle Hymn would rock if you have X cost burn spells (Bonfire of the Damned, Fireball, Disintegrate, etc.) to let loose later in the game. Otherwise, by the time you're sitting on enough creatures to really get a lot out of it, you likely don't need it.

You definitely need more Arms Dealers, as those will give them another target to worry about, as they provide you with spot creature removal (even big ones).

Goblin Chirurgeon, Mons's Goblin Raiders, Goblin Tinkerer, and Mogg Flunkies could all be replaced with more useful goblins. Goblin Balloon Brigade is just one option that comes to mind. In any case, these are the cards you'll drop for either those other ramp spells, more burn spells, or the lords mentioned above.

If you're going to have 50,000 goblin tokens, why not include 2x Burn at the Stake? Those give you a NASTY removal spell that can also win the game for you.

Lastly, in my experience, Coat of Arms could be a good option here, but keep in mind that it can backfire. Coat gives that bonus to ALL creatures that share a creature type, whether they're yours OR your opponent's. This means that if they're sitting on a few flyers (a noticeable weakness here), if they share a creature type, you put the Coat down and they could easily get the best of you. As an alternative, since you're going legacy, would be to rock something like Door of Destinies. You simply name "Goblin" and watch the counters add up.

OR, if you wanted to splash white, you could include some fun cards like Cathars' Crusade for pumping your goblins while also protecting yourself a bit with Safe Passage or things of that like.

It's a good start, but sadly, if you ever hope to play in a legacy tourney and be competitive, you'll need to drop a lot more cash on this. Honestly, it would be easier to make the deck standard and perhaps do well at some FNMs.

Thanks for the advice, this deck will be for casual play mostly. It will be nice to put a little more strength to it unfortunately my magic budget is very low at this time, mostly trying to get things through trade, which is not easy considering most of what I have is uncommons and commons.

Even if you want to be pretty casual it's pretty cheap to get standard goblins, I'd even send you what I've got since I dislike goblins, but FNMs are a really fun event even without a competitive style deck, and goblins tend to be consistent so you could easily win games because you've got the consistency that other decks don't have.

Other than that I agree about the Arms Dealer but not the Goblin Chirurgeon, how many kill spells that people actually use have a cannot regenerate clause? And if you do get a really powerful goblin like a Cheiftain, King or Krenko, Mob Boss out and they Doom Blade or Murder it then you can easily sacrifice a token you've got to save your best creature.

Overall I'd say this is a really solid start for a casual goblin deck, I do agree about the goblin Balloon Brigade if you get some though, it can push some damage through and block fliers which goblin decks can have issues with. I'd also recommend the Burn at the Stake as TyWooOneTime mentioned, even if you only use Krenko once it's still an awesome burn spell. Lastly I'd recommend Chancellor of the Forge, it's an underrated card for goblins In my opinion, if you go first and have one in your hand you do damage to your opponent without spending any mana and since you've got Rummaging Goblins you can just dump it later if you don't have the mana to cast it.