Hello,
We went to LA last year but we stopped in Anaheim.. We did go to Santa Monica though.. We used Viator website & booked our transfers with them with super shuttle i think.. Its around 10 each way.. which isnt bad in my opinion.. I think someone said to us taxis can rack up quite an expensive bill depending on traffic etc & then of course tip..
The super shuttle was located right outside the airport doors to the right, just saw the guy with the clipboard under the sign handed him our voucher & off we went.. no problems, and i shall be booking our san francisco ones with them too shortly..
I saw you mentioned in the Vegas thread about Disney & Universal, we did both as being in Anaheim Disney was on our doorstep.. and we booked a package with VIP tours to Universal studios for the day with transport included.. they had an office in Anaheim, but you can also book via their website..
We also did like a city tour with them aswell, which was really good!!