Hey guys, I just found a nice chart that helps you keep track of how many kills you need to level (Assuming the creatures are the same level as you)
Total
Lvl|| XP|| Xp|| Xp/kill|| Kills/lvl|| total kills
1 400 400 50 8 8
2 900 1300 55 16 24
3 1400 2700 60 23 47
4 2100 4800 65 32 80
5 2800 7600 70 40 120
6 3600 11200 75 48 168
7 4500 15700 80 56 224
8 5400 21100 85 63 287
9 6500 27600 90 72 360
10 7600 35200 95 80 440
11 8800 44000 100 88 528
12 10100 54100 105 96 624
13 11400 65500 110 103 727
14 12900 78400 115 112 840
15 14400 92800 120 120 960
16 16000 108800 125 128 1088
17 17700 126500 130 136 1224
18 19400 145900 135 143 1367
19 21300 167200 140 152 1520
20 23200 190400 145 160 1680
21 25200 215600 150 168 1848
22 27300 242900 155 176 2024
23 29400 272300 160 183 2207
24 31700 304000 165 192 2400
25 34000 338000 170 200 2600
26 36400 374400 175 208 2808
27 38900 413300 180 216 3024
28 41400 454700 185 223 3247
29 44300 499000 190 233 3481
30 47400 546400 195 243 3724
31 50800 597200 200 254 3978
32 54700 651900 205 266 4244
33 58600 710500 210 279 4524
34 62800 773300 215 292 4816
35 67000 840300 220 304 5120
36 71600 911900 225 318 5438
37 76100 988000 230 330 5769
38 80800 1068800 235 343 6113
39 85700 1154500 240 357 6470
40 90700 1245200 245 370 6840
41 95800 1341000 250 383 7224
42 101000 1442000 255 396 7620
43 106300 1548300 260 408 8028
44 111800 1660100 265 421 8450
45 117400 1777500 270 434 8885
46 123200 1900700 275 448 9333
47 129100 2029800 280 461 9794
48 135100 2164900 285 474 10268
49 141200 2306100 290 486 10755
50 147500 2453600 295 500 11255
51 153900 2607500 300 513 11768
52 160400 2767900 305 525 12294
53 167100 2935000 310 539 12833
54 173900 3108900 315 552 13385
55 180800 3289700 320 565 13950
56 187900 3477600 325 578 14528
57 195000 3672600 330 590 15119
58 202300 3874900 335 603 15723
59 209800 4084700 340 617 16340
60 n/a 4084700 345 0 16340
[1] XP per monster the same level as the player
[2] Assumes target is same level as player
*EDIT*
I just this second found lots of guides...Ill post them up if you want