Hi shaun,
The bay tree has male and female flowers on seperate trees, so if you have a female tree which would produce seeds, you will need a tree with male flowers close by before pollination can take place and for seed to set.
ripe seed, I think would be around september time but this may well vary by 2 or 3 weeks, according to location.
If however you wish to propergate and raise your own plants, a far simpler way is by taking cuttings.
If you are lucky enough to find sucker growth around the base of the trunks, then these can be detatched and will root very easily in a 2" pot of compost, at this time of year.
Other wise you can take 4" (10cm) stem cuttings ( just below the buds) in late summer but they will need a heated propergator for best results. Good Luck Tbird+