White lions are usually fielded at 21-30 strong, 3 ranks deep (7x3, 8x3, 9x3 or 10x3).
Characters and core, depend on the build. Some people will go for an Archmage and BSB only. Others will go add a scroll caddy to allow Scroll + Book of Hoeth Archmage. Annointed usually turns up with double Archmages (High + Beasts) and a block of Phoenix Guard to form a deathstar with a 3++, MR2, ITP, mages in the back and fighty Noble BSB + Annointed with possible Wildform/Savage Beast for damage. Such lists usually don't have enough points for a block of White Lions and enough shooting. Some other builds such as a Cav Bus (Lv4, Mounted Prince + BSB, additional nobles and or scroll caddy to taste) and ETC Star Dragon (Star Dragon Prince, BSB on foot, Lv4, scroll caddy) do exist, using completely different character settups.
In short, with High Elves, you can spend any amount of points on characters from the basic Lv4 + BSB to 50%+ of your army points.
If you have some time and want to see more army builds, have a look at the
Army Blogs section of the forum. Some of the really interesting blogs are the ones by Tethlis, Malossar, Swordmaster, Axiem, Seredain, wamphyri101, John Rainbow and Furion. All of them have army lists, ideas, battle reports showing multiple ways to play high elves. Do note that some of those blogs started under the 7th ed high elf book, so some sections aren't as relavent any more.