Would suggest getting ther very early for a ground pass. I didn't realise when I was last there in 2009 and arrived about 10.30 and didn't get in until 5.
If you just want the experience and chose your day, you can get a ground pass for about £20 with minimal queuing. They then often have tickets for court 1 or centre court for an additional amount.
I went on women's semi final day in 2012 and got in without queuing. I saw Djokovic practicing. Much as I would have liked to see Mr M I don't cope with crowds. I have applied for tickets in the ballot this year but if I am lucky would much prefer the earlier rounds when it is less manic.