You can use the front page to check your ads (please note the default date range is set to Yesterday, so you will not see current activity).
You do have another choice however, on the Reports tab, is a large number of options to track how much activity there has been on your ads, with a lot of various ways to get a better breakdown of activity over time.
Please note that whilst we try and update activity as close to real time as possible, if there is a heavy server load there can be delays. We will prioritize showing clicks over impressions, so that you have the more immediately useful information available to you.
If your ads are running, but you aren't seeing any activity, it may be that you need to increase your bid, or add more keywords (if applicable). Generally it's worth giving 24 hours to see if changes to an ad have had a positive effect.