You'll want to time your easterly transit (Buzzards Bay to Cape Cod Bay) to start anytime after the slack before the flood at the CCC Railroad Bridge. The current is favorable for about six hours and will hit it's max flow of around 4 knots about 3 hours after the slack.
Times for specific dates and additional info is available at
Tides.INFO: Ocean and river tide predictions for Cape Cod Canal (railroad bridge), Massachusetts Current
You can also get current times at
Current Station Locations and Ranges
Find CC Canal on the page and click on "predictions" on the far left side for the various current stations in the Canal.
If your boat will do 5-6 knots through the water I'd recommend you try to hit the west end of the canal just before max flood (at the RR Bridge) and you'll fly through in an hour or so. Last time we did it we were doing 11+ knots over the ground.
Re impact of wind: The current runs out into CC Bay for a mile or so. If you have a strong northerly it may get rough at the canal exit, but you can avoid the wind-vs-current problem more easily on the CC Bay side by getting outside the current flow with a turn to either side of the canal exit.
Wind-vs-current is a much tougher problem going the other way (CC Bay to Buzzards Bay). The west side of the Canal has a long run down a channel with a sand spit to stbd as you exit the canal. If you've timed your transit for max positive current (max ebb) AND if the prevailing SW'ly wind is up to 20-25 knots (as it's been known to do in the summer) you're in for a very rough ride down this channel. I did it once at night and it was not fun --prop was cavitating and water was washing over the bow as we hobby-horsed our way down the 2-3 mile channel into a 4+ ft short chop. In making an east to west transit with a SW'ly blowing in BBay, it's best to ride the last of the ebb and exit at or near slack water.
There are several places before the canal to anchor to time your passage -- Pocasset, Hadley Harbor, Onset (tricky entrance) are a few. There are mooring balls at the entrance to the Canal a mile or so before the RR bridge on the southeast side of the Canal (to stbd on the eastward transit). The moorings are behind a series of pilings that line the side of the canal in this area. The moorings are in a pool surrounded by shoal water, so don't enter through the pilings. (I tried it once and ran aground). Look for the channel into the pool to the E of the rock pile past the last piling. I've never been in there but I've seen sailboats moored there. If you decide to stop there, go slow and feel your way in.
PS. I'd second the recommendation above to buy Eldridge.