Cycling in France

On Saturday I'm heading to France for a spot of cycling, and planning on viewing part of stages 2 & 3 of Le Tour along the way. Never been cycling in France before, in fact I haven't been there at all since I was about 5.
Any hints/tips/advice?
The first specific query I have is regarding which types roads can I / can I not cycle on? I'm sure I'll have other ponderings, but for a start I'm open to any tips/ideas others may have, I'm pretty set on where I'm heading to each day, so it's more general stuff I'm after?
For instance I've plotted a route on BikeRouteToaster.com, but it's got me on what appear to be some pretty major roads... I've no idea if this is correct or not! I've used a few extra track points to force it to stay off the major roads, and this ends up being 10k shorter...
Any hints/tips/advice?
The first specific query I have is regarding which types roads can I / can I not cycle on? I'm sure I'll have other ponderings, but for a start I'm open to any tips/ideas others may have, I'm pretty set on where I'm heading to each day, so it's more general stuff I'm after?
For instance I've plotted a route on BikeRouteToaster.com, but it's got me on what appear to be some pretty major roads... I've no idea if this is correct or not! I've used a few extra track points to force it to stay off the major roads, and this ends up being 10k shorter...
Rides a Cannondale Synapse 105.
0
Posts
Routes nationales are the equivalent to British A roads. In my experience best avoided because of the volume of traffic, but no doubt there are quiet ones.
Routes departmentaux - everything from 'B' roads to very quiet country lanes and dirt roads. These are your best bet.
Chemins communaux - country lanes. Only shown on more detailed maps.
Don't be disturbed by drivers beeping you when they are about 100m behind and about to overtake you. It's a friendly warning so that you're not surprised by them, not a "get out of my way".
Also every village should have a drinkable water fountain, usually in the centre near the church or school.
D roads are what I had aimed my route planner at, although I had done so on the basis that they were thinner yellow roads instead of double red lines, but at least I'm on the right track.
Particularly pleased to hear about the cafe's & patisseries, and quite looking forward to using some of the French I learnt at GCSE 10 years (really??) ago!