Can anyone please help with info on buses and trains in LA to major attractions etc such as downtown, Universal Studio, Santa Monica Pier /Venice Beach and Hollywood. Is it easy to get to these places using public transport or drive a hired car?

I wouldn't even consider going to LA and not renting a car.

When I think of "LA" and "public transport," the first term that comes to mind is "vestigial." Sorry, you will need to hire a car.

In spite of the other posts, if you really are travelling only between Downtown, Hollywood and Universal, you could do it all easily, cheaply and conveniently by the red line subway. To get to Santa Monica and Venice would require bus travel, which is a drag - slow, very slow.
Here is a link to the LA MTA maps:
http://www.mta.net/metro_transit/sys...system_map.htm

Are you staying downtown LA? If you want to go to SM Pier, you can take the Big Blue Bus #10. It travels from downtown SM to downtown LA. Just look for the triangular Big Blue Bus sign.
You can also go to Venice Pier from SM via big blue bus. Go to www.bigbluebus.com.
Depending on where you're staying in downtown la, you can take the red line to Universal Studios. go to www.mta.com
Hope that helps.

Am staying downtown at this stage, if it's safe...
Thanks for all the response fo far. It's encouraging to know that public transport is Ok ! I've heard lots of bad posters on this subject.

We had a car, but didn't want to deal with parking issues at the Getty, so we took a bus. Lots of other tourists had the same idea. No problem.

Downtown LA is getting better and better and the improvements include safety. Downtown is actually a pretty convenient location, since public transportation is readily available. You can hop on the Dash shuttle and pick up the transportation at nearby Union Station.

As an la native I would recommend renting a car because public transportation is possible, it's hard to use and not practicle for a tourist. Also remember to avoid certain areas at crunch time.