MySQL Indexes

[Tompkins Neil]

Hi,

Can anyone help and offer some advice with regards MySQL indexes.  Basically
we have a number of different tables all of which have the obviously primary
keys.  We then have some queries using JOIN statements that run slowly than
we wanted.  How many indexes are recommended per table ?  For example should
I have a index on all fields that will be used in a WHERE statement ?
 Should the indexes be created with multiple fields ?  A example  of two
basic queries

SELECT auto_id, name, score
FROM test_table
WHERE score > 10
ORDER BY score DESC


SELECT auto_id, name, score
FROM test_table
WHERE score > 10
AND name Like '%Red%'
ORDER BY score DESC

How many indexes should be created for these two queries ?

Thanks,
Neil