Well, I can give you a few tips!
First of all, Welsh is very sing-song. So get up a nice rhythm between each syllable, take your time with them.
Ll, rh and ch are all letters in their own right in Welsh.
Ll is a funny sound - sort of a weird mix of l and sh. Put your tongue up against the roof of your mouth and breath out!
Rh is quite simple, you just go hhrrrhhh. Roll your r and aspirate it a lot.
Ch is a similar sound to Bach or loch. I am so good at saying phrases like 'chwech o'gloch' when I'm full of phlegm!
Something that's difficult to describe, though, is the sound 'o' makes in Welsh. You make your mouth and lips very round, and it's somewhere in between oh and or (in a British accent - stay well away from 'flat' American aahhhs!). Take your time, make it a nice long vowel. This one's really hard to explain except by example. It's not exactly necessary but it makes the words sound so much better.
So Gallod Rhosyn Bach would be like this:
Gallod - gall-llod, with the ll sound. Slight emphasis on first syllable, perhaps.
Rhosyn - rhoss-in, with the rh sound and emphasis on the first syllable.
Goch - goch, with the ch sound.
Now, most English people would have the os as straight forward British-sounding os - rhyming with top or pot or whatever. Pott, not paahhht. But it's better if it's got the nice round o sound.
Do you know what the name means? Callod is the stem of a bean, potato or grass (dunno why it's mutated), rhosyn is rose, and coch is red (again, dunno if it's supposed to be mutated or not).
Welsh is a very easy to read language, once you know what the letters are supposed to sound like. There's no weird combinations like in English tough or whatever - the letters always sound the same no matter where they are in the word. The hard part is learning the sounds that are so different to English ones!
If you believe everything you read, better not read.