First off, I just have to say one thing: Market Place. As far as I know, there is no reason not to use them. 2 gold for 3 with the only restriction being the clan you play. There is no downside to using them. Well, there are Bandit Hideouts... like I said, no downside.
Ok, now what? you've got 3 gold producing holding for a 40 card deck. After this, there are several ways to go. First off, I'm going to mention a gold chain. Since this is a Crane site, and I've started off with Market Place, the next place to go is Port. Port produces 2 gold plus 1 for each Market Place. So this can produce up to 5 gold from your deck, up to 8 gold if your opponent plays Market Places, and even more in multiplayer. The average that it produces will be around 3, maybe 4, so it is pretty good for being cost effective. It helps even more if it becomes part of the bigger chain.
The next link in this chain is Pearl Divers. It is only 1 gold, and it produces 1 gold plus 1 gold per Port. There's not much to say about this that hasn't been said about the Port, but it is cheaper, and it really shines if you use Kosaten Shiro. It's free! And it is head and shoulders above a Small Farm because it starts out with 1 gold, but can grow to 4 or more.
There are a couple more links that can be added to this chain. There is Island Wharf, which connects to this chain because it is considered a port. Therefore, it adds to the Pearl Divers that you have. The only downside to this is that it will only produce 1 gold unless you are a Yoritomo's Alliance player. And, it costs 1 gold. The upside to this is again Kosaten Shiro, which makes it like a Small Farm, except that it increases the gold production of your Pearl Divers. There is also Pearl Beds. But unless you're a Naga player, it only produces 1 gold plus 1 for each Pearl Diver. It also costs 2 gold, and it doesn't contribute to anything else.
There's also Trading Grounds, which produces 3 gold, plus 2 for each Market Place. However it costs 8 gold, which is a bit much unless you have some really hefty priced cards in your deck. It will definatly give you a lot of gold though, which can be handy for a larger deck with bigger guys for a nice multiplayer game. Otherwise, it's just overkill.
A good card to help this gold chain is Restoring the Doji Treasury. This card'll help you get a marketplace in early game to start off the chain, or it can get you the card you need to best compliment the chain you already have. While an opponent may just get a Jade Works for 3 gold, you could get a Market Place which could give you 3 gold right away (via 3 Ports) and another 3 gold when it unbows. And, although it doesn't reduce the cost for Kosaten Shiro, it let's you search for an already free one, or any one at normal Kosaten cost.
If you're wondering what I personally use, with Kosaten Shiro, there's 3 Market Places, 3 Ports, 3 Island Wharfs, and 3 Pearl Divers. And it works quite fine for me. Hope you like this, and if you would like to contribute, or suggest something. Just E-Mail me and let me know.
Additional: While the gold chain I describe generally does well, there are faster options, that you would have to look into for tournament play. However, for casual play, and for beginners, this is a viable option, with cards that are very plentiful and easy to get. Which was what this was intended for.