Not to discourage you, but it literally took my contractor 3 days to install my farmhouse sink. They were really nervous about it because they had never done it before, but luckily it came out well. Here's what they did:

1) They made a template based on the shape of the front of the sink. First they made a template out of cardboard, tested it to make sure it fit well with no gaps (they went through several iterations) and then once they got a good cardboard template they transferred it onto a piece of plywood.
2) Then they used the plywood template to cut out the front of the sink cabinet -- this was the scary part
3) Then they installed little 'shelves' (about 2" wide, running the the length of both sides of the sink cabinet) for the sink to sit on
4) The sink was 'loose' (meaning it was just sitting on the side support shelves not glued in our anything) until the counters were installed. When the counters where templated, they marked the sink in pencil (traced the outline of the sink along the cabinet edge) to show how far out it was supposed to be so that it would be in the same spot when the counters were installed.

Here's how it looked in the end:

My recommendation would be to find someone who has done this before...

Another thing you need to decide before the counters are templated is what kind of reveal you want (positive, negative, or neutral) -- check out the atticmag.com sink gallery below for examples. I literally showed the Momto4Kids example to the templaters and told them to copy it.

Here is a link that might be useful: kitchen sink gallery

Let me just give you this advice: Measure and template 5 times before you do it. My DH did a great job himself and the cutout was perfectly flush with the sink -- AND THEN one of his moron friends told him the that the height he had it at would make a little valley between the counter and sink and collect water- so he elevated the sink and had the counters installed w/ the sink above the counter- I wanted to leave it the way it was. (this almost led to the end of our marriage) But my DH is sooo stubborn and now I have a huge gap below it- he says he'll make a filler piece and we won't notice it AND water still collects on the outside of the sink and rolls forward and drips on the floor. I could deal w/ the water if it at least looked nice. Good luck! I do love the sink though :)

thanks for the advice
hoffman: it looks like they installed a wood strip that runs inside your cabinets on both sides, do the slats then run accross the inside of the cabinet attached to those two slats every two inches? is the sink held in place by the counter tops being laid on top of it? sorry we haven't had the best of luck with people so its better if i can tell them exactly what to do!

No, there are no slats running across the bottom of my sink from one side to the other -- there are just the two little shelves on along each side of the cabinet. The sink is attached to the counter top with caulk and I guess the weight of the counter is really what holds it in place.

disclaimer: I'm not an expert & I didn't do the work! I'm just sharing my observations of what they did...

My sink sits on a shelf that was built into the cabinet, but it basically performs like the wood shelf does. My husband and I shimmed it to drain, but the weight of the sink held it in place. Then the countertop went on (copper over mdf for this location) and we caulked it into place. Plumber plumbed it. Voila!

Ours sits on a plywood shelf which is part of the cabinet DH built. Probably overkill but DH wasn't taking any chances once he lifted that sink and knew how much it weighed. lol! Scroll down to the pic with the cat in the sink and you can see the shelf/top of the base cabinet. once he had it positioned just right he drilled a large hole fro the drain.

As for the sink install, do make a template as has been suggested and trial fit it before cutting your cabinet. We used foamcore, which you can buy at craft stores, but cardboard would work, as well.

Good luck! If you need more help email me and I'll get DH to respond.

Here is a link that might be useful: sink base

angelcub--your husband did a great job!

I have a 3618 and my contractor built 2 supports, one underneath each of the 2 short sides of the sink, and then a front center support. He also reinforced the sink cab box underneath where the weight would be transferring through the cab (i.e., underneath his 2 support shelves).

I am no engineer, but he said the majority of the weight is carried on the 2 short side walls of the sink, and that is where most of your support system needs to be concentrated. Now I'm wondering if I should ask him to put an additional support in the smack-dab center of the sink. He sounded like he knew what he was talking about, though, when he was explaining that from a physics perspective the weight is on the edges not in the center of the sink (thus no need for an entire shelf - though if I were building it I would have built an entire shelf!!!). :)