There are many Welsh resources available online, including the following:
Everything is online these days - and you need a Welsh portal to it. Here are some options for Welsh language web browsers:
Google Chrome - How to change the default language of Google Chrome
To deal with the plethora of emails that invade our inboxes daily, here are some programs that are available in Welsh:
Microsoft Outlook - see the Welsh language packs for Microsoft Office below.
Mozilla Thunderbird - Not yet available in Welsh yet, but worthy of note.