*Full disclosure: I've not completed the ISEB certification, however prior to moving to development I managed a QA/Test team of 5, two of who had completed the foundation certification.*

My suggestions are:

 - Remember, this is similar to every other qualification that you've ever done so the same basic principles hold true:

  - *Plan:* Put together a study plan so you know what you should be studying and when. You need to ensure that this is achievable in the time you have available
  - *Organise:* Keep yourself organised. If you're a lists person, write lists. If you like using your Outlook calendar to organise yourself, put all your study periods into that.
  - *Keep Notes:* Lists, brainstorms, bullet points, paragraphs, flowcharts; whatever works for you to act as a quick reference that helps you refresh your memory.
  - *Balance:* This does tie back to "Plan" to an extent. Don't over work yourself. This isn't school, college, or university, you're holding down a full time job *and* studying. Make sure you strike the right balance because if you don't, studying for ISEB will make you miserable. That isn't likely to result in a good grade.

 - As far as the ISEB is concerned, it has been known to be called a little, errr, "dry". Persevere though, it does add value to your day to day working skillset.
   - Can you find opportunities to introduce things you're learning into your day-to-day role? **There's no better way to reinforce theory than practice** (If you can't, why are you studying towards it?).
   - Do you have any colleagues who're certified (ISEB that is, not the other certified! =) and can act as a sounding board for ideas or to help you grasp concepts you may struggle with?
   - Don't forget, now that sqa.stackexchange exists, there'll (hopefully!) be a lot of people here that you can apply my prior point to.

Whilst none of this is *particularly* specific to ISEB, hopefully it'll be of some help to you in your studies!