BQM51

One option  

Here's a possible way of playing. After playing 1-6 to weaken White's group at the top, Black can start attacking the white group on the right with 7. With the threat of the extension at a and peeps against the cutting point at b, the top group is far from safe. And whatever side White plays on, Black keeps the two white groups separated with a move around tengen.

Continuation  

If White runs with his group on the right, these moves will keep up a strong attack on both sides. After this sequence, White will have to defend against the connection at a.

- Herman, 1k KGS.

First strengthen the lower left  

In my view Black should first reinforce the weak group in the lower left with 1 and 3. This looks ahead to an invasion at a at some future time.

The biggest point on the board might be near the marked white stone - for example at b. Black can play there next, if given a chance. An attack in the centre isn't likely to be successful until Black has an overall stronger position.

Charles Matthews