Anyone in France can you advise on train ticket purchases please?

[Notquitegrownup]

Will post under Travel too, as this is really a holiday question, but we are off to St Malo area in three weeks, and fancy a day trip to Paris.

Are French train tickets available online as in the UK, and if so, can you recommend a link to a valid site?

Thanks

[Notquitegrownup]

Sorry, should have googled first! Isn't the SNCF site easy to use?! Do hope that the UK sites are as easy for overseas travellers over here.

Paris here we come!