Hi cosmid,
I suggest you begin by calculating descriptive statistics for your variables. For continuous variables such as age, year etc this will be mean, standard deviation, median, minimum, maximum, first and third quartiles. Plot the histograms to see the distributions. For categorical variables such as gender etc calculate the frequency and percentages.
Then, proceed with examining univariate associations between pairs of variables. Look at the scatter plot and correlation coefficient (Pearson or Spearman, whichever is appropriate) for pairs of continuous variables such as age and year. For continuous and categorical variable pairs use a t-test/ANOVA/non-parametric analysis of variance depending on the nature of your variables (this is why previous step is important).
Further, find out why these data where collected in the first place - what was the purpose of the study? What questions were asked/hypotheses made? Accordingly, proceed with examining multivariate associations among your variables.
Regards,
Olga