It is now August 2009, and to be frank I am somewhat disappointed with my first steps in keeping Mason bees, perhaps it would be a good idea to start at the beginning of the year so I should 'back up the bus' to the start of the year.
I finally tracked down a supplier of Mason bees, in fact a number of them all in British Columbia, just couldn't find a dealer in Ontario. In fact I couldn't find anyone keeping BOBs in Ontario, looks like I'm the only one.

Bees are sold in quantities of 10, they come in a variety of packaging, the ones I got were in a phial and also small cardboard boxes, as I bought from two suppliers. I didn't want all my eggs in one basket, one supplier might be too big a gamble but with two it would be doubtful to have a complete failure. BOBs are sent through the regular mail just like honey bees, usually by Express post. These should be kept cool, but not initially in the fridge, as they can dry out and become desiccated. I did learn later they can be kept in the crisper tray with an occasional wet cloth added to the container, to aid humidity.

My bees duly arrived and as I have a 'cold room' or some call it a root cellar I decided to keep them in there for the winter. The temperature stays approximately 50 degrees Fahrenheit all winter long, and as we also use it as a cheese cave we keep the humidity around 80% which should have been perfect. They arrived just before Christmas and were placed in storage ready to be released in the early spring when the blossoms are at 'pink bud' stage, just a few days before they're fully open.

Spring came, the trees looked good, but we suddenly had a temperature rise to 57 Fahrenheit in the storage area, as the bees start emerging at 55 Fahrenheit, this spelt disaster. Sure enough I opened the door to find Mason bees crawling over the floor, walls and ceiling. They had eaten their way out of a cardboard box lined with styrofoam. Quite incredible when you consider the distance they had to chew through.

I quickly rounded them up, picking up each one and placing them into an empty Mason jar. Needless to say they didn't want to stay inside, so it was quite a fight to corral these bees, subdue them and get the lid in place. I couldn't leave them in the jar, active, so decided to cool them off in the fridge over night, planning to release them in the morning. This quieted them down, come the morning of release it was pouring down with rain, almost all day. So even though BOBs do fly in cooler wet conditions than honey bees I decided that a downpour was too much to expect, leaving them for an extra day I figured wouldn't do any harm.

They were duly released, placed in the release area of their nest site. That was the last we saw of a number of them, in fact at one point I thought they had all moved elsewhere, as they were nowhere in sight. I should point out, there were some that hadn't emerged, about 10 cocoons in total actually emerged in the nest site, along with the free flying chilled bees.

On a daily basis I watched for bees at the site and also amongst the fruit trees. It was disappointing to see the odd one, moving very, very quickly through the blossoms. I watched and counted about 5 or 6 bees around the nest site coming and going, entering and leaving during warm days.

It's now the end of August and the nest site has been taken down to prevent the 'nasties' from damaging the tube entrances. Counting the mud plugs on the end of each cell, 12 in total, means in effect I have increased the population to 36, plus drones of course.
This should give us a better population than the 20 I started with, and provided I do a better job on releasing them in 2010 then the pollination should be much better.

All it leaves me to do from here is to take the nest box apart and clean the cocoons thoroughly to prevent pollen mites from infecting next years bees. As this isn't done till late October/November you'll need to revisit about that time to access the whole year.

In the meantime should you wish to access bees and materials for next year here are the suppliers I used.

Bee Diverse these folks will supply a good selection of bee houses and bees, but do require advance booking of bees
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Mason Bee Homes Gordan proved to be helpful, backed up his service with advice, also a supplier of hand made bee houses and bees.

Doing a search on Google for "Mason Bees" will turn up numerous University and informational sites on the benefits, ways and means of keeping Mason bees or BOBs.

Update
In early November I pulled the nest boxes apart to clean the cocoons getting them ready for next year (2010) and I must say straight out I'm disappointed yet again.

Bear in mind, I had problems with the release which reduced the population before I got started, now I find quite a number of cocoons badly damaged by mould. Using my experience of Honey bees I know that mould in bee hives spells trouble. Mason bees are no different, this mould turned out to be a version of chalk brood as the damaged cocoons contained hard mummified bodies, the loss caused a decline,so the population hardly grew at all.

Looking around one or two of the online forums dealing with BOBs they provided the answer to the this problem. Plastic. As with honey bees, plastic is not appreciated by BOBs and numerous folks report problems with mould while using plastic nest tubes. I supposed I should have spent even more time on my research of BOB nesting preferences.

I wrote to the suppliers Bee Diverse and while they didn't admit to a problem they did send me a replacement made of compressed corn material. Obviously I cannot say if this is a good move or not, as it will require a season to test them out, Time will tell.

While this was all going on I had an e mail from a gentleman in BC who made me an offer of barter. He would supply me with nest trays and a quantity of cocoons in exchange for some cheese, which I make as a hobby during the winter. Got to keep the hands busy. How does the saying go "The devil makes work for idle hands"?
His email address Pasquale     I'm grateful to him for his helpful advice.

Needless to say I jumped at the chance of more bees, plus a sample of his designed nest trays. To be honest I tried but couldn't reproduce his trays, so I modified them yet again. His tray is a through drilled 6 inch block into which he inserts a rolled paper insert, plugged at the back end. One of the neatest and smoothest designs I have seen.
This is the best design to date, it should prevent the damp problem, allow for easy cleaning by withdrawing the tube, and more importantly allow me to build a decent population.

Looking back making the trays was a labour of love, the time I wasted making just a few extra trays really wasn't worth the effort. It would have been simpler and definitely cheaper to have purchased them, but that is the nature of beekeepers 'Spend $500 of time, to save $5 of cash'.